Significant Differences In Elevation Research Articles

Estimation of open-pit / underground mining cross-effect in complicated geomechanical conditions

The paper presents the results of prediction model studies of the stress–strain behavior in Gakman field of Yukspor deposit during hybrid open pit/underground mining under conditions of high tectonic stresses. The mountainous relief, rock mass faulting with a series of weak structures, geometry of the ore body, the actual and design parameters of stopes, and mining operation under the uncaved overlying stratum with three-sided support are taken into account. Based on the multivariate threedimensional stress–strain modeling using the finite element method, geomechanical substantiation of simultaneous open-pit and underground mining was carried out. It has been established that the geomechanical determinants in Gakman field are: – gravitational and tectonic stresses with a significant excess of the tectonic component over the gravitational component; – mountainous relief of ground surface with a significant elevation difference in the study area; – location of underground mining under the uncaved overlying stratum with three-sided support; – faulting of rock mass with a series of weak structures (Gakman fault); – formation of the open pit and crown pillar above underground mine; – significant lag of the mining front on the underlying levels of level + 320 m. The dimensions of the cross-effect zone and crown pillar when the underground operations approach the open pit mine are determined.

Bristow versus Latarjet in high-demand athletes with anterior shoulder instability: a prospective randomized comparison.

BackgroundTraumatic anterior shoulder instability is a common disease, especially in young athletes. The Latarjet and Bristow techniques are nonanatomical surgeries that involve the transfer of the coracoid process to the anterior border of the glenoid and are indicated in cases at a high risk for recurrence and in the presence of associated bone lesions. Studies have evaluated the recurrence and complications associated with these techniques, but they have important differences, and should not be considered synonymous. The objective of this study was to prospectively compare the Bristow and Latarjet techniques in high-demand athletes. Hypothesis: Bristow and Latarjet techniques lead to similar results.Patients and methodsThirty-seven athletes (41 shoulders; three athletes underwent bilateral surgery) with anterior recurrent dislocation of the shoulder that was surgically treated using the Bristow or Latarjet technique were prospectively analyzed. The follow-up time was 5 years. The mean age was 26.4 years (range: 16-46 years). In 17 cases (41.5%), the dominant side was not affected.ResultsElevation and external rotation (passive and active) decreased in the early postoperative period and achieved values in the final follow-up similar to those found in the preoperative period. The mean postoperative scores at 5 years were as follows: ASES, 79.1 (range: 66-95); ASORS, 77.8 (range: 60-100); WOSI, 52.6 (range: 18-77); and VAS, 1.88 (range: 0-6). All of the results presented statistical significance. There was a complication rate of 9.75% in the follow-up period. There were no new dislocations after the surgery. Most (75%) of the athletes returned to the sport after the surgery, and there was no correlation between poor results and any of the variables studied. There was a statistically significant difference in passive external rotation in favor of the Latarjet technique four weeks after surgery (P = .01). We also found a statistically significant difference in passive elevation in favor of the Latarjet technique eight weeks after the surgery (P = .04). When we compared the Bristow and Latarjet techniques regarding the ASES, ASORS, and WOSI scores, we found no statistically significant difference. In the comparison regarding whether the athletes returned to sports, we found no statistically significant difference.ConclusionThe Bristow and Latarjet techniques lead to good results in athletes with no new dislocation episodes and are suitable for treating patients with anterior recurrent dislocation of the shoulder. The Latarjet technique showed better results in some of the variables studied.

Prosthetic joint infection in culture-negative and alpha-defensin-positive patients versus culture-positive and alpha-defensin-negative patients: a retrospective cohort study of the differences in clinical characteristics and outcomes

Background: Culture-negative (CN) prosthetic joint infection (PJI) poses a challenge for the clinician for both diagnosis and management. We compared the clinical presentation and outcomes between patients with CN alpha-defensin-positive PJI and culture-positive (CP) alpha-defensin-negative PJI. Methods: This was a retrospective study of 15 patients who underwent treatment for PJI (four hips and 11 knees) at a tertiary referral center by a single surgeon from 2016 to 2019. Patients were divided into two cohorts based on their culture results: one group had negative cultures but positive alpha-defensin test (n=7) and the other had positive cultures but negative alpha-defensin test (n=8). These two cohorts were compared in terms of clinical presentation, laboratory values, treatment duration, and functional outcome. Statistical analysis was performed on variables of interest. Results: Patients in both PJI groups most commonly presented with pain and swelling of the involved joint. There was a greater proportion of CN PJI patients with a history of infection, such as bacteremia or urinary tract infection (UTI) requiring antibiotics, than CP PJI patients (42.9% vs. 0%). There was no statistically significant difference in inflammatory marker elevation for either group. Only 57% of the CN PJI patients underwent surgical debridement versus all CP PJI patients. There were no differences in outcomes at final follow-up between the two groups. Conclusions: Prior history of infection requiring antimicrobial therapy is a risk factor for negative cultures. CN PJI is not a negative prognostic indicator and results in outcomes similar to CP PJI. Level of Evidence: Level III.

Onward but not always upward: individualistic elevational shifts of tree species in subtropical montane forests

Ongoing global climate change is driving widespread shifts in species distributions. Trends show frequent upwards shifts of treelines, but information on changes in montane forest below the treeline and in the tropics and subtropics is limited, despite the importance of these areas for biodiversity and ecosystem function. Patterns of species shifts in tropical and subtropical regions are likely to be more complex and individualistic than global averages suggest due to high species diversity and strong influence of competition, alongside direct climatic limitations on distributions. To address the question of how subtropical montane tree species are likely to move as climate changes, we used an extensive national forest inventory to estimate distribution shifts of 75 tree species in Taiwan by comparing the optimum elevation and range edges of adults and juveniles within species. Overall there was a significant difference in optimum elevation of adults and juveniles. Life stage mismatches suggested upward shifts in 35% of species but downward shifts of over half (56%), while 8% appeared stable. Upward elevation shifts were disproportionately common in high elevation species, whilst mid to low elevation species suggested greater variation in shift direction. Whilst previous research on mountain forest range shifts has been dominated by work addressing changes in treeline position, we show that although high elevation species shift up, below the treeline species may shift individualistically, heralding widespread changes in forest communities over coming decades. The wide variation of responses indicated is likely driven by individual species responses to interacting environmental factors such as competition, topography and anthropogenic influences across the broad range of forest types investigated. As global environmental changes continue, more detailed understanding of tree range shifts across a wide spectrum of forests will allow us to prepare for the implications of such changes for biodiversity, ecosystem function and dependent human populations.

The Influence of an Attachment-Related Stimulus on Oxytocin Reactivity in Poly-Drug Users Undergoing Maintenance Therapy Compared to Healthy Controls.

BackgroundSubstance use disorders (SUDs) have been described as a dysfunctional way to compensate for deficiencies in that person’s underlying attachment system. Furthermore, the neuropeptide oxytocin (OT), which is a critical component of the neurobiology of the attachment system, has been shown to effectively reduce addictive behavior and therefore has been discussed as a potential medication in SUD treatment. This study investigates variation in peripheral OT plasma levels as a function of exposure to an attachment-related stimulus in SUD patients compared to healthy controls (HCs).MethodsA total sample of 48 men, 24 inpatients in maintenance treatment who were diagnosed with poly-drug use disorder (PUD) and 24 HC, was investigated. A 15-min exposure to the Adult Attachment Projective Picture System (AAP) was used as an attachment-related stimulus and coded for attachment status. Blood samples before and after the AAP-assessment were taken and assayed for OT levels. Variation in baselines level of OT was examined in relation to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), the Adult Attachment-Scale (AAS), and the Brief Symptom Inventory (BSI).ResultsFollowing the AAP stimulus controls showed no significant difference in OT levels elevation from baseline compared to the PUD group’s OT levels. Furthermore, in the PUD group only OT-baseline-levels may be negatively associated with the AAS subscale “Comfort with Closeness” and “Anxiety” and lifetime substance use.DiscussionOur results suggest that peripheral OT levels in poly-drug users undergoing maintenance treatment are not significantly different in responsiveness to an attachment related stimulus compared to HC. With regard to non-significant tendencies observed in this study which hint toward decreased OT-reactivity in the PUD group, further research is needed to explore this hypothesis with increased statistical power.

Noninvasive treatment of pectus excavatum with a vacuum bell combined with a three-dimensional scanner

Our aim was to evaluate the effect of a vacuum bell (VB) combined with a three-dimensional (3D) scanner for the noninvasive treatment of pectus excavatum (PE). A VB was used to create a vacuum at the anterior chest wall with a patient-activated hand pump, and it should be applied regularly for more than 2h each day at home. Eighty-two patients required to be followed up every three months were included in this retrospective study and distributed into four stages (stage 1: treated for 3months, stage 2: treated for 6months, stage 3: treated for 9months, and stage 4: treated for 12months). In addition, the deformity in the chest wall was scanned by a 3D scanner at the clinic, and the 3D depth (3D-DE) and 3D Haller index (3D-HI) of PE were calculated through Geomagic studio 2013 software. Eighty-two patients (12/2017-12/2019) met the criteria at the clinic, and 24 patients (29.3%) achieved excellent correction (3D-DE ≤ 3mm). When comparing the improvement in 3D-DE and 3D-HI of PE to the patient's treatment time, a statistically significant difference was observed between stages 2 and 1 (3D-DE p<0.01, 3D-HI p<0.01), stages 3 and 2 (3D-DE p<0.01, 3D-HI p<0.01) and stages 4 and 3 (3D-DE p<0.01, 3D-HI p<0.01). There was a statistically significant difference in sternum elevation between patients aged <10years and those aged ≥ 10years (3D-DE p = 0.006, 3D-HI p = 0.045) and patients with symmetrical and asymmetric PE (3D-DE p = 0.042, 3D-HI p = 0.032). However, there was no statistically significant difference in sternal elevation between males and females (3D-DE p = 0.27, 3D-HI p = 0.495). The main side effects were moderate subcutaneous hematoma, petechial bleeding, thoracalgia and chest tightness. With controllable side effects, noninvasive treatment for PE with a VB combined with a 3D scanner is safe, objective and radiation free, and the initial results to date are encouraging. Patients aged <10years, with symmetrical PE and treated for over 12months may achieve a better outcome.

Transabdominal Ultrasound Imaging of Pelvic Floor Muscle Activity in Women With and Without Stress Urinary Incontinence: A Case-Control Study.

Transabdominal ultrasound (TAU) is an easy and noninvasive way to evaluate and retrain pelvic floor muscle (PFM) function. The purpose of this study was to compare PFM activity in women with and without urinary incontinence (UI) by measuring bladder base displacement (as a marker for PFM activity) using TAU during PFM contraction, Valsalva's maneuver, and abdominal curl. Sixty-three women, aged 20-55 years, volunteered to participate in this cross-sectional study: 21 were continent and 42 had UI (21 stress urinary incontinence [SUI] and 21 mixed urinary incontinence [MUI]). Mean bladder base displacement in millimeters was measured to evaluate differences between the three groups (continent, SUI, and MUI) and also between the continent and UI groups during the performance of each maneuver. No significant differences were seen between the three groups in bladder base elevation during PFM contraction (P > 0.05). Descent of the bladder base during Valsalva's maneuver and abdominal curl was significantly greater in women with SUI and MUI than in women in the continent group (P < 0.05). Comparison of the continent and UI groups showed no significant differences in elevation of the bladder base during PFM contraction, while descent of the bladder base was significantly greater in women with UI than in women in the continent group during Valsalva's maneuver and abdominal curl (P < 0.05). TAU indicated that bladder base descent was greater in women with SUI and MUI than those in the continent group during the performance of maneuvers that increased intra-abdominal pressure. This effect may be due to decreased PFM performance in women with urinary incontinence.

Morpho-tectonic control on the distribution of C3-C4 plants in the central Himalayan Siwaliks during Late Plio-Pleistocene

The Siwalik deposits of the Himalayan foreland basin (HFB) preserve the Late Miocene-Pleistocene record of the Himalayan tectonics, monsoonal variation and the expansion of C4 plants. Previous vegetation reconstructions emphasized the Late Miocene expansion of C4 plants with an implicit assumption that the vegetation thrived in the floodplain of lowland rivers. The coarsening-upward sequence of the Siwalik Group suggests deposition in an alluvial fan setting in which the Lower and Middle Siwaliks are deposits of distal region whereas the Upper Siwaliks represents a proximal region of the fan. The modern alluvial fans forming in the Himalayan foothills show a significant difference in elevation (ca. 300 m) and vegetational composition between their proximal and distal regions. In the HFB, the elevation difference is expected to be more pronounced due to the surface uplift of Siwalik deposits along the Himalayan Frontal Thrust (HFT). The increased elevation would have affected the vegetation distribution in the Upper Siwaliks which implies that the vegetation in the proximal part of the fan might not represent lowland floodplain. However, the vegetation composition is less understood from the Upper Siwaliks region due to the scarcity of conventional proxies in these younger foreland deposits.In this context, δ13C values of bulk soil organic matter (SOM), n-alkane and n-alkanoic acid in the paleosols were measured from Late Mio-Pleistocene Siwaliks at Surai Khola (Nepal) to comprehend the impact of elevation on vegetation distribution in the HFB. The results suggest most commonly observed expansion of the C4 plants at ca. 7 Ma, and a unique second phase of expansion of C3 plants post-3 Ma. The higher δD values of n-alkane and n-alkanoic acid suggest that the climate was drier in the last 4 Myr; most likely driven by the onset of the Northern Hemisphere Glaciation (NHG). The growth of C3 plants was favored due to cool climatic conditions induced by a higher elevation in the proximal part of the fan. Water-bearing conglomerates in the Upper Siwaliks may have helped the C3 plants to thrive in a relatively drier climate. This multi-proxy paleovegetation reconstruction demonstrates a morpho-tectonic control on the abundance of C3-C4 plants in the Siwaliks with the possible influence of NHG.

Keratoconus Screening Among Myopic Children.

AimTo assess the topographic corneal changes and the incidence of keratoconus among children with high myopia.SettingsIt is a prospective study, in which 174 eyes of children with high myopia were studied in the period between August 2015 and June 2018.MethodsAll patients were examined to assess the refractive error and corneal examination using Scheimpflug camera to evaluate different corneal parameters.ResultsStudied children aged between 6 and 14 years (11.05±1.98). Males represented 54% of the cases (n=94). The mean spherical error was −7.75±2.97 ranging from −6 to −13.50D. The mean cylindrical error was −4.12±1.78D (−1 to −8). Regarding corneal examination, data recorded were those about maximum K reading (kmax), thinnest location, highest anterior and posterior elevation in 4mm zone, and higher-order corneal aberrations. Analysis of the obtained data revealed 16 eyes (9.2%) with keratoconus. These eyes were considered as a separate group and compared with the remaining eyes. There was significant difference in kmax (p= 0.03), anterior elevation, and posterior elevation (p=0.01 for both). Regarding myopia or astigmatism, there were no significant differences when compared with normal eyes. But high myopia with low astigmatism were found in five eyes of them (31.2%). The main statistically different aberrations were vertical coma (−2.04±0.99) (p=0.01) and spherical aberrations (−0.9±0.78) (p=0.02). Regarding gender, there were 11 eyes in boys (68.7%), and this was statistically significant (p=0.01). Vernal keratoconjunctivitis with frequent eye rubbing was found in 6 eyes (37.5%).ConclusionChildren with high myopia irrespective of the degree of astigmatism may have corneal abnormalities which are more pronounced in cases with vernal keratoconjunctivitis. Corneal examination should be performed for highly myopic children to detect any corneal abnormality and to treat it as early as possible.

Multivariate analysis reveals phenotypic diversity of Euscaphis japonica population.

Fruit traits affect population genetic diversity by affecting seed protection and dispersal strategies, thereby comprising important components of phenotypic variation. Understanding of the phenotypic variation is an indispensable first step for developing breeding strategies. However, little information is known about the genetic variation in E. japonica—a monotypic species with abundant phenotypes that is mainly distributed in southern China. In this study, we evaluated the phenotypic diversity of 67 E. japonica using 23 phenotypic traits. Our results showed that the Shannon–Wiener (I) index of qualitative traits ranged from 0.55 to 1.26, and the color traits had a relatively high I. The average coefficient of variation of compound leaf traits (14.74%) was higher than that of fruit and seed traits (12.77% and 11.47%, respectively). Principal component analysis also showed that compound leaf and fruit traits were important components of total variation. Furthermore, correlation analysis revealed a significant difference in elevation and fruit color, irregular ribs, leaf margin and texture. The F value within populations was smaller than among populations, indicating the variation in phenotypic traits among populations was much greater than within populations. Dehua and Zunyi populations had the highest coefficients of variation, whereas Wenzhou population had the smallest—which may be attributed to habitat destruction. According to Q-type clustering, 67 samples clustered into four groups, with those having similar phenotypes clustering into the same group. In general, leaf and fruit traits had abundant phenotypic diversity, representing the main sources of phenotypic variation. Combined with clustering results and field surveys, this study suggests that the phenotypes of E. japonica are classified into two main categories: The deciduous E. japonica present at high altitudes; and the evergreen E. japonica present at low altitudes. Excavating E. japonica variations provides a theoretical reference for its classification and diversity, and is of great significance for planning genetic resources and establishing conservation strategies.

The Tarim Basin and the Transformation of its Landscapes

The study of ancient crop farming in the arid lands of central Asia (Tuva Depression, Ubsunur Hollow, and Central Mongolia) revealed unique characteristics of the paleogeography of the studied regions, i.e., the prior occurrence of forest-steppe vegetation on currently desert landscapes. In the opinion of the authors, the main reason for the environmental change is anthropogenic, specifically, the destruction of the forest cover, which causes a decrease in groundwater levels and subsequent desertification. From the perspective of the results obtained for the Tarim Basin landscapes, the research presumes that the anthropogenic factor was determinant in the desertification of its area. The natural features of the basin and its surroundings (high-elevation mountainous terrain, glaciers as a water source, active volcanoes, fertile foothill plains, mineral resources, and climate) and the economic advantages of geographic location at a trade crossroads predetermined the emergence of large focal point for the formation of Asian ethnoses in this area; this led to a major anthropogenic impact on the basin ecosystems, which ultimately resulted in landscape degradation and the emergence of deserts (Taklamakan Desert). The desertification processes were augmented by specific relief features, i.e., the rather significant differences in elevation between the basin margins and floor, its endorheic nature, natural disasters associated with volcanic eruptions and melting of glaciers, and the insignificant amount of precipitation. Russian researchers believe that, in the distant past, there was an occasional eruption of people relocating from large focal points of the development of early civilizations to other territories due to the large population size, human energy, and social problems (Gumbatov, 2018). The “exodus” of the tribes from a scanty hollow of the Tarim Basin towards the Mongol Steppe could have been one of the manifestations of those “eruptions.” This can be further supported by the origin of a sacral image of Odugen in the area of the modern-day volcanism in the Eastern Sayan and Khangai Mountains, which appears to have been preserved since the distant past and to be related to the deification of the active volcanoes in the Kunlun Range skirting the Tarim Basin. Another wave of migration from the desertified Tarim Basin was apparently directed toward the Indus Valley, where, in symbiosis with the indigenous population, it gave rise to the Vedic Period. The severe anthropogenic impact on the environment in the Indus Valley and adjoining areas played a part in the formation of new desert landscapes (Thar Desert). The proposed material can be, to some extent, considered a working hypothesis.

Assessment of Various Measurement Methods to Assess First Metatarsal Elevation in Hallux Rigidus.

Background:While metatarsus primus elevatus (MPE) has been implicated in the development of hallux rigidus, previous studies have presented conflicting findings regarding the relationship between MPE and arthritis. This may be due to the variety of definitions for MPE and the radiographic measurement techniques that are used to assess it. Additionally, previous studies have only assessed elevation of the first metatarsal with respect to the floor or the second metatarsal, and not with respect to the proximal phalanx. The aim of this study was to examine the reliability of new radiographic measurements that consider the elevation of the first metatarsal in relation to the proximal phalanx, rather than in relation to the second metatarsal as previously described, to assess for MPE. In addition, we aimed to determine whether the elevation of the first metatarsal was significantly different in patients with hallux rigidus than in a control population.Methods:A retrospective chart review was conducted from prospectively collected registry data at the investigators’ institution to identify patients with hallux rigidus (n = 65). A size-matched control cohort of patients without evidence for first metatarsophalangeal (MTP) joint arthritis was identified (n = 65). Patients with a previous history of foot surgery, rheumatoid arthritis, or hallux valgus were excluded. Five blinded raters of varying levels of training, including 2 research assistants, 1 senior orthopedic resident, 1 foot and ankle fellowship-trained orthopedic surgeon, and 1 attending musculoskeletal fellowship-trained radiologist, evaluated 7 radiographic measurements for their reliability in assessing for MPE in hallux rigidus and control groups. Four of the 7 were newly designed measurements that include the relationship of the first MTP joint. Inter- and intrarater reliability were calculated using intraclass correlation coefficients (ICCs) and categorized by Landis and Koch reliability thresholds. The measurements between the hallux rigidus and control populations were compared using an independent t test.Results:Six of the 7 radiographic measurements were found to have substantial to almost perfect interrater reliability (ICC, 0.800-0.953) between all levels of training, except for the proximal phalanx–first metatarsal angle, which showed moderate reliability (ICC, 0.527). Substantial to almost perfect intrarater reliability (ICC, 0.710-0.982) was demonstrated by the measurements performed by research assistants. All 7 of the measurements taken by the musculoskeletal fellowship-trained radiologist demonstrated significant differences in first metatarsal elevation between the hallux rigidus and control populations, with the hallux rigidus group showing increased elevation (P < .001-.019).Conclusion:This study confirmed the reliability of 7 radiographic measurements used to assess for MPE, including 3 previously established and 4 newly described measurements. Observers across all levels of training were able to demonstrate reliable measurements. In addition, the measurements were used to show that patients with hallux rigidus were more likely to have MPE compared with patients without radiographic evidence for first MTP arthritis. These measurements could be used in future work to examine how the presence of MPE relates to the etiology and progression of hallux rigidus, and how it affects the results of operative treatment.Level of Evidence:Level III, retrospective comparative study.

Titelbild: Bautechnik 2/2019

AbstractZum Titelbild The transformation of an area originally used for railway maintenance into a new neighbourhood in the city centre is one of the most important urban development projects being carried out in Bristol. The new St Philips footbridge spans the River Avon contributing to provide the needed accessibility for development to a site previously isolated by several infrastructures and the watercourse. The footbridge is an innovative solution to a complex crossing problem: the connection of two banks with a significant elevation and appearance difference and one of them being developed to high architectural standards faster than the other. (Foto: Knights Architects)

Hydrogeochemical and Isotopic Constraints on the Pattern of a Deep Circulation Groundwater Flow System

Characterization of a deep circulation groundwater flow system is a big challenge, because the flow field and aqueous chemistry of deep circulation groundwater is significantly influenced by the geothermal reservoir. In this field study, we employed a geochemical approach to recognize a deep circulation groundwater pattern by combined the geochemistry analysis with isotopic measurements. The water samples were collected from the outlet of the Reshui River Basin which has a hot spring with a temperature of 88 °C. Experimental results reveal a fault-controlled deep circulation geothermal groundwater flow system. The weathering crust of the granitic mountains on the south of the basin collects precipitation infiltration, which is the recharge area of the deep circulation groundwater system. Water infiltrates from the land surface to a depth of about 3.8–4.3 km where the groundwater is heated up to around 170 °C in the geothermal reservoir. A regional active normal fault acts as a pathway of groundwater. The geothermal groundwater is then obstructed by a thrust fault and recharged by the hot spring, which is forced by the water pressure of convection derived from the 800 m altitude difference between the recharge and the discharge areas. Some part of groundwater flow within a geothermal reservoir is mixed with cold shallow groundwater. The isotopic fraction is positively correlated with the seasonal water table depth of shallow groundwater. Basic mineral dissolutions at thermoneutral conditions, hydrolysis with the aid of carbonic acid produced by the reaction of carbon dioxide with the water, and hydrothermal alteration in the geothermal reservoir add some extra chemical components into the geothermal water. The alkaline deep circulation groundwater is chemically featured by high contents of sodium, sulfate, chloride, fluorine, silicate, and some trace elements, such as lithium, strontium, cesium, and rubidium. Our results suggest that groundwater deep circulation convection exists in mountain regions where water-conducting fault and water-blocking fault combined properly. A significant elevation difference of topography is the other key.

St. Philips footbridge in Bristol

AbstractThe transformation of an area originally used for railway maintenance into a new neighbourhood in the city centre is one of the most important urban development projects being carried out in Bristol. The new St Philips footbridge spans the River Avon contributing to provide the needed accessibility for development to a site previously isolated by several infrastructures and the watercourse. The footbridge is an innovative solution to a complex crossing problem: the connection of two banks with a significant elevation and appearance difference and one of them being developed to high architectural standards faster than the other. The design should be appropriate for both immediate and medium‐term scenarios and to harmoniously coexist with the close existing bridges and the future buildings. The bridge is a 50m‐span and 4‐m wide steel beam with a forked geometry, hosting a ramp for disabled and cyclists and a staircase as part of its own structure to maximise functionality. The design approach to generate its shape was at the same time structural, aesthetical, and functional. Thanks to this holistic approach, the bridge is compact, simple, elegant and clearly legible for both footbridge and river path users.

Analysis of the accuracy of the gradient method for determining the mean integral refractive index of air

The article is devoted to the problem of improving the accuracy of taking into account the influence of the Earth’s atmosphere on the results of distance measurements carried out using electromagnetic waves. The main influencing factors in such measurements are the difference between the speed of propagation of an electromagnetic signal in the atmosphere and the speed of light in a vacuum, as well as the refractive distortion of the trajectory along which the signal propagates.To eliminate the influence of the atmosphere, special corrections are used, which are applied into the measurement results in order to compensate for the above influencing factors. The most important among them is the correction, which takes into account the mean integral refractive index of air along the trace being measured.At present, as a rule, model methods for determining the correction are used, taking into account the mean integral refractive index of air. These methods use a point approximation of continuous functions describing the spatial distribution of temperature, pressure and air humidity on the trace being measured, as well as the representation of the finite sum of a certain integral specifying the exact correlation for the correction. Due to these limitations in the framework of the commonly used model methods, it is not always possible to achieve the required accuracy of the results of distance measurements. As for the well-known hardware methods, which are potentially more accurate, they are still under development. In this regard, new possibilities of improving the accuracy of model methods, in particular, the recently proposed gradient method, are considered.Theoretical studies of the accuracy of the gradient method for determining the mean integral refractive index of air in distance measurements on near-Earth traces are carried out. It is shown that it is more accurate than the well-known trapezium method. The equations of measurement of the gradient method obtained with the use of Hermite interpolation polynomials, which are valid for non-uniform partition of the measured trace by points in which the local values of the refractive index are determined, are considered. The requirements for the procedure and accuracy of measurements of the parameters necessary for determining the gradients of the refractive index of air at the end points of the trace in the framework of the gradient method are substantiated.The results of the studies provide a rigorous justification for new methods for determining the mean integral refractive index of air on near-Earth traces with a non-uniform profile of the underlying surface in the presence of significant elevation differences.

Characterization of elevation and land cover dependent trends of NDVI variations in the Hexi region, northwest China

In the arid Hexi Corridor of northwest China, vegetation cover plays a pivotal role in sustaining the unique terrestrial ecosystem. In this paper, vegetation changes during growth season from April to October were investigated through examining the trends in the Normalized Difference Vegetation Index (NDVI) across the Hexi region. Based on the GMMIS NDVI 3g.v1 dataset, NDVI trend and its dependency on elevation and land cover were analyzed for the period 1982–2015 according to multiple statistical tests. Results showed that NDVI exhibited a significantly increasing trend in ∼70% of the vegetated area, in contrast with a negative trend only in 2.85%. The resulting distinct groups with respect to decreasing, increasing and no trends presented significant differences in elevation and land cover composition, and the correlation between elevation, land cover and NDVI trend magnitude was subjected to precipitation and temperature change. The elevation and grassland cover were found to mainly account for variations in NDVI trend, and increase in elevation and various types of land cover excluding impervious and bare land would facilitate the trend magnitude. The dependency of NDVI trend on elevation and land cover was very vulnerable to increasing air temperature, which triggered an improvement in the vegetable activity to adapt to climate change, especially grass and forest. The contribution of crop and shrub to NDVI change was sensitive to precipitation trend change, but the crop was primarily influenced by human activities. The identified patterns of vegetation change would help to gain insights into the adapting mechanism of the fragile ecosystems in arid areas to changing environmental conditions.

Sensitivity and response of low-nutrient lakes to post twentieth century environmental change in New Brunswick, Canada

A paleolimnological approach was used at 45 mostly remote, low-nutrient lakes in New Brunswick (NB), Canada, to determine bioindicator responses and lake sensitivity to post twentieth century environmental change. From each undated core we assessed zooplankton (Cladocera) change between discrete time periods using related assemblage metrics, including the rise of Bosmina sp., cladoceran richness, and average assemblage body size. Cladocerans from a pre-industrial interval (20–20.5 cm) were compared to those from a present-day interval (0–0.5 cm). Lakes were then classified as either high- or low-sensitivity based on assemblage metrics, and sensitivity group differences in physical–chemical measures were tested for significance. Compared to pre-industrial times, Bosmina sp. relative abundance increased in 33 of 43 lakes (75% of lakes surveyed) by on average 20%. Body size and rarefied species richness of assemblages decreased significantly. These ecological shifts detected at an important intermediate trophic level are attributable to indirect effects of climate change, although we cannot rule out shifts in fish predation and littoral habitat as additional structuring factors. Eighteen lakes were classified as high-sensitivity lakes and showed significant differences in latitude, surface area, elevation, dissolved calcium and magnesium concentrations, and conductivity compared to 25 low-sensitivity lakes. In high-sensitivity lakes, richness decreased on average by 6 species and body size decreased by 0.2 mm. This study presents a historical context for constructing effective conservation and management efforts at a time of substantial environmental change in low-nutrient NB lakes.

Foredune morphodynamics and sediment budgets at seasonal to decadal scales: Humboldt Bay National Wildlife Refuge, California, USA

Coastal foredunes are shore-parallel ridges that form in the backshore and their morphodynamics are controlled partly by seasonal and spatial variations in the coastal (onshore) sediment budget that, in turn, are driven by oceanic and atmospheric processes and interactions, including regional wave and wind regimes, climatic variability events (e.g., ENSO), sediment availability, beach characteristics (e.g., width, slope), and vegetation type and cover in the backshore. Previous studies on shoreline change in Northern California report only broad rates of erosion and accretion related to regional meteorological regimes. This study presents a more detailed, multi-decadal to seasonal account of shoreline response and foredune morphodynamics along a 2.5 km stretch of coast in the Humboldt Bay National Wildlife Refuge (HBNWR). Analysis of historical aerial photography (1939–2014) reveals trends in shoreline position that are coupled with more detailed assessments of foredune morphodynamics and seasonal scale volumetric changes from cross-shore topographic profiles``. These findings set the historical context of foredune morphodynamics and allow exploration of the implications of seasonal meteorological variation on long-term (75-year) foredune evolution and development at the HBNWR.DSAS describes maximum foredune progradation in the north (up to +0.51 m a−1) and maximum foredune retreat in the south (up to −0.49 m a−1). Aerial photograph analysis (2004–2014) shows statistically significant larger erosive features in the southern zone than in the northern and central zones. Seasonal volume calculations from cross-shore profiles indicate statistically significant differences in alongshore transect elevation and foredune volume, with larger elevations and volumes in the northern and central zones than in the southern. Combined with evidence of seasonal bidirectional littoral drift, these data support a north to south gradient in sediment availability, foredune position and resulting stages of established foredune development. Seasonal storm energies and climate forcing events introduce variability in erosive patterns but support the persistence of alongshore developmental stages. Future research should explore foredune morphodynamics on a smaller spatial scale and changes related to the presence/absence of multiple vegetation assemblages.

THE COMPARISON OF DEEP NECK FLEXOR STRENGTHENING EXERICISE WITH MCKENZIE NECK EXERCISE FOR NECK POSTURE CORRECTION ON STUDENTS WITH FORWARD HEAD POSTURE AT SMA N 1 SEMARAPURA

This study aims to compare deep neck flexor strengthening exercise intervention with mckenzie neck exercise to correct the neck posture of student with forward head posture. Using experimental design with Pre-Test and Post-Test Group Design involves a sample of 24 people divided into 2 groups. Group I was given deep neck flexor strengthening exercise intervention and Group II was given mckenzie neck exercise intervention. Hypothesis Test using paired sample t-test obtained result p = 0.592 with average difference in Group I 7.58 ± 4.39 whereas Group II got difference mean 8.5 ± 3.84. These results showed no significant difference in craniovertebral angle elevation before and after intervention in both groups.&#x0D; Keywords : forward head posture, craniovertebrae angle, deep neck flexor strengthening exercise, mckenzie neckexercise,