Valve Length Research Articles

Two new species of the diatom genus Meridion (Bacillariophyta, Tabellariaceae) from Aleutian Islands

Two new species of Meridion (Bacillariophyta, Tabellariaceae) are described from Unalaska Island (Aleutian Islands, USA) based on light and scanning electron microscope investigations. Meridion tenuipes sp. nov. is characterized by very slender valves with capitate headpole, lack of costae at the footpole and rimoportula positioned close to valve apex. Meridion humerosum sp. nov. possesses more robust valves with capitate poles, separated by distinct shoulders, costae distributed through the whole valve length and rimoportula displaced some distance from the apex. Comparison of these new species with other heteropolar representatives of the genus is provided. Our data indicate that the degree of Meridion endemism in North America is even higher than it was previously supposed.

Leveraging artificial intelligence for the management of postoperative delirium following cardiac surgery

BACKGROUND Postoperative delirium is a highly relevant complication of cardiac surgery. It is associated with worse outcomes and considerably increased costs of care. A novel approach of monitoring patients with machine learning enabled prediction software could trigger pre-emptive implementation of mitigation strategies as well as timely intervention. OBJECTIVE This study evaluates the predictive accuracy of an artificial intelligence (AI) model for anticipating postoperative delirium by comparing it to established standards and measures of risk and vulnerability. DESIGN Retrospective predictive accuracy study. SETTING Records were gathered from a database for anaesthesia quality assurance at a specialised heart surgery centre in Germany. PATIENTS Between January and July 2021, 131 patients had been enrolled into the database and had data available for AI prediction modelling. After exclusion of incomplete follow-ups, a subset of 114 was included in the statistical analysis. MAIN OUTCOME MEASURES Delirium was diagnosed with the Confusion Assessment Method for the ICU (CAM-ICU) over three days postoperatively with specific follow-up visits. AI predictions were also compared with risk assessment through a frailty screening, a Shulman Clock Drawing Test, and using a checklist of predisposing factors including comorbidity, reduced mobility, and substance abuse. RESULTS Postoperative delirium was diagnosed in 23.7% of patients. Postoperative AI screening exhibited reasonable performance with an area under the receiver operating curve (AUROC) of 0.79, 95% confidence interval (CI), 0.69–0.87. But pre-operative prediction was weak for all methods (AUROC range from 0.55 to 0.66). There were significant associations with postoperative delirium: open heart surgery versus endovascular valve replacement (33.3% vs. 10.4%, P < 0.01), postinterventional hospitalisation (12.8 vs. 8.6 days, P < 0.01), and length of ICU stay (1.7 vs. 0.3 days, P < 0.01) were all significantly associated with postoperative delirium. CONCLUSION AI is a promising approach with considerable potential and delivered noninferior results compared with the usual approach of structured evaluation of risk factors and questionnaires. Since these established methods do not provide the desired confidence level, improved AI may soon deliver a better performance. TRIAL REGISTRATION None.

Гидравлическое сопротивление системы управления движением инспекционного снаряда с клапаном обтекаемой формы в газопроводе низкого давления

The main problem while developing inspection shells for low-pressure gas pipelines is mainte-nance of their uniform motion under the action of the pumped gas. In the present work, we propose a solution to this problem based on changing the cross-section of the central flow channel of the smart pig by moving an axially symmetric valve along the axis of the channel. Two types of valves with a drop-shaped and a cone-shaped front part were considered. The choice of the valve shape and size can be made by calculating the forces acting on the smart pig during gas flow. The prob-lem was solved by the methods of computational fluid dynamics under the assumption of axial flow symmetry. The gas was considered to be compressible. The calculations showed that the total force acting on the valve and walls of the flow channel does not depend on its shape and, depending on the valve position, can change by more than two times. The optimum length of a drop-shaped valve is nearly half that of a conical valve. Although the drop-shaped valve produces a more inhomoge-neous velocity field than the conical valve, the former is more acceptable for regulating gas flow through the central channel of the inspection smart pig.

Morphometry of the internal structures of the graylag goose (Anser anser) heart

As a result of our research, it was found that the heart of the graylag goose Anser anser is a hollow muscular organ weighing 28.950±0.08 g in females (relative 0.73%), 29.091±0.09 (0.69%) in males, with a length: ♀ 51.55±0.07 mm, ♂ 52.66±0.08; it is oval, slightly elongated. Auricular appendices are oval, slightly elongated, in size: the right one with a length ♀14.98±0.05 mm, ♂ 15.57±0.06; with a width ♀ 21.99±0.0 mm, ♂ 22.23±0.05; their wall thickness data are as follows: ♀ 0.47±0.05 mm, ♂ 0.49±0.06; left – ♀ 12.27±0.05 mm, ♂ 12.98±0.06; ♀ 14.89±0.07 mm, ♂ 15.04±0.08; ♀ 0.71±0.03, ♂ 0.78±0.02 mm, respectively; the convex base. The pectineus muscles are located in the walls of the auricular appendices. From the interatrial crest, four to eight pectineal muscles extend, which are connected by smaller muscles, thereby forming a finely looped network. The left ventricle is ♀ 40.97±0.09 mm long, ♂ 41.05±0.08; with a width ♀ 14.89±0.09, ♂ 14.98±0.09; wall thickness ♀ 8.29±0.05, ♂ 8.35±0.07. It contains a tricuspid valve, which has three cusps: septal, caudal, lateral. The right ventricle is ♀ 31.39±0.05 mm long, ♂ 31.49±0.05; with a width ♀ 6.29±0.03, ♂ 6.39±0.05; wall thickness ♀ 2.89±0.03, ♂ 2.91±0.04, has a crescent-shaped atrioventricular opening. The valve length is ♀ 19.17±0.04 mm, ♂ 21.17±0.05 mm.

Return to the Shellfish Beds: New Insights on Use of California Sea Mussels (Mytilus californianus) and Turban Snails (Tegula spp.) Based on Harvesting Experiments

ABSTRACT Sea mussels and turban snails are among the most abundant mollusks recovered from central California middens. Experimental harvests of these and other shellfish have been conducted to help interpret archaeological findings, but methodological complications have plagued many of the early experiments. Here we report results of harvest experiments of mussels and turban snails completed between 2016 and 2022 on the Pecho coast of San Luis Obispo County. We developed a local formula to convert umbo thickness measurements into whole mussel valve length, and this article reports new return rates, including one of over 1,500 kcal/hour for mussels obtained by an experienced shellfish collector. This rate demonstrates the importance of accumulated knowledge in subsistence experiments, and suggests that mussels have higher dietary potential than previously thought. Archaeological mussel size profiles suggest that a selective (plucking-like) strategy was associated with sustainable harvest for at least the last 5,000 years on the Pecho coast.

Size matters? Species- and size-specific fish predation on recently established invasive quagga mussels Dreissena rostriformis bugensis Andrusov 1897 in a large, deep oligotrophic lake.

Since its first appearance in Lake Constance in 2016 the invasive quagga mussel Dreissena rostriformis bugensis has come to dominate the mussel community and now occurs in hyperabundant densities over the whole lake bottom. A lake-wide field study was conducted between 2019 and 2020 to obtain a systematic insight into the importance of this novel source of potential prey for the native fish community. In total 664 fish of 20 different species were caught and their digestive tracts were analysed. Meanwhile, quagga mussels were sampled to assess their calorific energy value by size and season. Regressions of septum length on maximum valve length were used to evaluate size-specific mussel consumption by the three dominant quagga-eating fish species. The study shows that nearly all benthivorous fish are able to forage efficiently on quaggas. However, in the case of one keystone species with very high commercial interest, the benthic whitefish Coregonus spp., quagga consumption is more limited as only individuals larger than 35 cm consumed quaggas in relevant amounts. The energy content of quagga mussels is positively size dependent with seasonal effect and elevated values during summer for medium- and large-sized mussels. Even at its peak, the calorific value of quaggas by weight is much lower than that of endemic aquatic invertebrates, while single mass is high. Future implications for fish stocks, food web integrity and possible fishery management options are discussed.

Predation of the crab Acanthocyclus albatrossis on seeds of the bivalve Mytilus chilensis under different environmental conditions: Importance of prey and predator size

Predation is one of the most important interactions in biology, playing a fundamental role in the ecology of populations and communities. In southern Chile, the mussel Mytilus chilensis supports a large aquaculture industry. This species cohabits with one of its predators, the crab Acanthocyclus albatrossis, both in wild bivalve beds and in suspended culture systems. In this investigation, we assessed the predator-prey interaction between these two species, addressing the following aspects: a) the vulnerability pattern of M. chilensis to predation by A. albatrossis; b) prey sizes that are free of predation (the refuge in size); c) the attack rate and d) the effects of temperature and salinity on predation by different-sized A. albatrossis crabs. The prey sizes most likely to be attacked were 7.5, 12 and 14 mm (valve length) respectively for the three predator size categories evaluated. The sizes of the mussels that are free of predation were > 12, > 18 and > 22 mm respectively for each predator size. The mean attack rate was affected by the size of M. chilensis, with the smallest prey (6–12 mm) exposed the highest predation pressure. Temperature exhibited a positive linear effect on the median attack rate only for crabs in the smallest size category; no pattern was observed for the effect of temperature on the other sizes of crabs. Salinity showed no evident effects on the median attack rate at any size category. Our results indicate that A. albatrossis could be an important predator of M. chilensis recruits in wild bivalve beds, and of seeds in suspended culture systems.

Multi-Center Analysis of Predictive Factors of Enteral Autonomy and Risk Factors of Complications of Pediatric Intestinal Failure in China.

ObjectivesThe aim of this study was to identify predictors for enteral autonomy and intestinal failure (IF)-related complications and evaluate the outcomes of a multi-center pediatric cohort in China.MethodsThe medical records of pediatric patients with IF treated at four medical centers in China from January 1, 2012 to November 31, 2020 were retrospectively reviewed. Enteral autonomy was defined as sustained growth and cessation of parenteral nutrition for >90 days. Multivariate logistic regression analysis was used to identify factors predictive of enteral autonomy and the risk factors of complications, such as IF-associated liver disease (IFALD) and catheter-related bloodstream infection (CRBSI).ResultsThe study cohort of 92 pediatric patients with IF included 71 (77%) who underwent surgery and 21 (23%) who received non-surgical treatment. Eventually, 63 (68.5%) patients achieved enteral autonomy by the end of the follow-up period. Multivariate logistic regression analysis indicated that longer duration of parenteral nutrition (PN), sepsis, and non-breastfeeding were risk factors for enteral autonomy. When considering the detailed intraoperative data, the presence of an ileocecal valve (ICV) and greater residual small bowel (RSB) length were reaffirmed as predictors of achieving enteral autonomy. Medium/long-chain (MCT/LCT) lipids or sepsis were identified as negative predictors for IFALD. Univariate analysis revealed that the use of MCT/LCT lipids was associated with a greater likelihood of CRBSI.ConclusionIn this cohort, enteral autonomy was achieved at a percentage of 68.5%, and the risk factors for not achieving enteral autonomy were a longer duration of PN, sepsis, and non-breastfeeding. The presence of an ICV and a greater RSB length were important predictors of achieving enteral autonomy.

Новые данные по морфологии некоторых широко распространенных и редких пеннатных диатомовых водорослей (Bacillariophyta)

This electron microscopy study of new for the Volgograd Region (Russia) Anomoeoneis sphaerophora f. sculpta, Gyrosigma wansbeckii, and Pleurosigma elongatum from mineralized tributaries (Bolshaya Samoroda, Lantsug and Khara) of the hyperhaline Lake Elton provides new data on the variability of quantitative diagnostic characteristics (valve length, number of striae and areolae in 10 μm) and some morphological elements (raphe and areolae). For Anomoeoneis sphaerophora f. sculpta, false areolae were found on the external valve surface, it was shown for the first time that the raphe ends are bent towards the primary side of the valve as well. For Gyrosigma wansbeckii, data on the areolae number in 10 μm are presented for the first time. The range of length and width of Pleurosigma elongatum valves, as well as the number of striae and areolae in 10 μm, has been expanded.

Новые данные по морфологии Achnanthes brevipes (Bacillariophyta)

This electron microscopy study of Achnanthes brevipes from mineralized tributaries (Solyanka, Chernavka, Khara) of the hyperhaline Lake Elton (Volgograd Region) provides new data on the variability of quantitative diagnostic characteristics (valve length, number of striae and areolae in 10 μm). Based on the original and published data, a refined diagnosis of A. brevipes is proposed. It is very similar to A. longipes in valve shape and quantitative characteristics, but striae are multi-row in the latter species and single-row in A. brevipes. A short note about the nomenclature status of A. brevipes is given.

Морфологічна мінливість деяких видів пенатних діатомових водоростей (Bacillariophyta) із водойм зони відчуження Чорнобильської АЕС (Україна)

This scanning electron microscopy study of the morphology of pennate diatoms (Achnanthidium eutrophilum (Lange-Bertalot) Lange-Bertalot, Aneumastis stroesei Mann et Stickle, Gomphonema italicum Kützing, G. pala Reichardt, G. vibrio Ehrenberg, Punctastriata ovalis Williams et Round) from phytoperiphytic communities in the cooling pond of the Chernobyl nuclear power plant and natural lakes of the Exclusion Zone (Glyboke and Daleke lakes) has revealed a higher variability in quantitative characteristics (valve length and width, number of striae in 10 µm). At the same time, no variability of qualitative features (shape of valve, axial and central area, raphe and striae arrangement) has been observed in these species. In A. eutrophilum, the number of striae in 10 µm differ from the published data, in A. stroesei – the valve length, in G. pala, G. vibrio and P. ovalis – the valve length and width. The range of variation in the number of striae in 10 µm in G. pala and the valve length and the number of striae in 10 µm in A. stroesei and G. italicum disagree with the literature data. The first electron micrographs of the inner surface of the valve and the corresponding data on its morphology are obtained for A. eutrophilum, A. stroesei, G. italicum, G. pala and G. vibrio.

Numerical investigation on nonlinear wave interaction with partially submerged subsea pipe-valve structures

The dynamic behaviours of subsea pipe-valve structures—the principal components of subsea equipment—are of critical concern for the control of the lowering through the splash zone during installation. Nonlinear interactions between waves and pipe-valve combinations are challenging the investigation of the wave forces acting on large-dimension structures. This paper proposes a numerical model to study the nonlinear hydrodynamic performance of partially submerged pipe-valve structures. A two-dimensional (2D) numerical water tank (NWT) was established to efficiently generate high-accuracy incident waves, and a semi-immersed horizontal cylinder was applied to the numerical simulations of wave-structure interaction (WSI) to study the mesh and time convergence. The numerical model was validated with a comparative analysis of the modelling results with experimental data, other numerical results, and theoretical results. Numerical simulations of the interaction between Stokes-II waves and subsea pipe-valve structures were performed, and the effects of the valve height ratio, valve length ratio, and valve spacing were investigated. The subsea pipe-valve structure is a kind of multi-scale structure, the wave forces exhibited stronger nonlinearity when acting on the partially submerged valves than on the completely submerged pipe. Changes in valve structure and distribution significantly increased the overall change in the wave forces acting on the valves. The stronger nonlinearity was primarily derived from phenomena such as wave reflection, wave blockage, and wave run-up. The numerical results provide references for the structure and strength designs and offshore installations of large subsea equipment like subsea manifolds.

Analysis of the type material of Gomphosphenia tackei (Bacillariophyceae) and comparison to epizoic diatom populations on freshwater snails

Background and aims – Hustedt (1942) originally described Gomphosphenia tackei from Germany under the name Gomphonema tackei. Because of the small cell size and the lack of scanning electron microscopy (SEM) images from the type material, it is often confused with other species from this genus, especially with G. stoermeri. The aim of this paper was to present detailed morphological characteristics of G. tackei based on the analysis of the type material and of several epizoic populations from Central Europe. Material and methods – The material in this study was collected from the shells of the freshwater snails Lymnaea stagnalis, Planorbarius corneus, and Planorbis planorbis. Additionally, for an unambiguous species identification, the type material for Gomphosphenia tackei was analyzed using light and scanning electron microscopes.Key results – The presence of Gomphosphenia tackei was confirmed in the studied material. The largest population (up to 19%) was recorded on the shell surfaces of living snails, whereas on empty shells, the diatom did not seem to be present or only in very low numbers. Valves are typically clavate with rounded apices. Valves are frequently observed in girdle view, often joint together in pairs. The valves in the studied populations had a valve length of 7–29 µm, a valve width of 3–4 µm, and a stria density of 25–29 striae in 10 µm. In the type population, valve length ranged from 7.5 to 27 µm with a valve width of 3.0–4.0 µm and a stria density of 23–29 striae per 10 µm. Striae were composed of 2–4 elongated to rounded areolae per stria. At the apices, the striae were composed of one single areola. The cells were attached to the substratum by their footpole.Conclusion – Published illustrations of Gomphosphenia tackei do not always correctly represent this species. Individual cells are attached to the substratum by secreted mucilage, probably via their areolae or girdle band pores located on the footpole.

Videographic conceptual dynamic representation of bicuspid aortic valve anatomic configurations and structural inter-relationships.

Videographic conceptual dynamic representation of bicuspid aortic valve anatomic configurations and structural inter-relationships.

Estuarine oiling increases a long-term decline in mussel growth

The ribbed mussel, Geukensia granosissima, cycles nutrients, contributes to soil stability, and can be a major component of predator-prey communities in salt marshes. Mussels were exposed to the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, and salt marshes remain contaminated eight years later. We hypothesized that the oiled mussels had reduced annual growth, altered population size frequency, and perhaps changed valve morphometrics. We sampled 10 marshes near Port Sulphur, LA, to measure the morphometrics of 133 mussels and their age-specific growth rate, and also the marsh oil content and percent vegetative cover. The relationships between valve weight, length and biomass weight were stable as mussels aged. A Year 1 growth decline from 1994 to 2018 is not easily explained by estuarine acidification, flooding, and temperature rise; freshening of estuarine waters is suggested to be a probable causal factor in the declining growth rate. The average valve length and dry biomass per valve declined with oiling in 2010. A multiple regression equation using the percent cover and oil concentration in 2018 described 70% of the variation in valve length. Sites with the highest oiling had few mussels with 14 annual growth bands and more of the younger mussels compared to sites with the lowest oiling. Valve growth in Year 1 declined for four years after the oil spill and was not compensated by higher growth rates in older mussels. Annual growth was below the amount predicted in a regression equation for the five years after the oil spill. Mussel populations may also have been structured by predators that were also responsive to oiling in subtle ways.

<strong><em>Sarcophagodes duodecima sp. nov.</em>, a new small araphid fossil diatom (Bacillariophyceae) from Lower to Middle Pleistocene sediments of Japan</strong>

A new fossil diatom species, Sarcophagodes duodecima, is described from the Lower to Middle Pleistocene Karato Formation of Himeshima Island, western Japan, based on detailed morphological observation of valves using light and scanning electron microscopes. This new species is characterized by a smaller valve length range, a wide lanceolate central area, shorter striae on the valve face, and longer striae on the mantle than other members of the genus. The new species was also found in the Lower Pleistocene Bushi Formation, central Japan, suggesting that S. duodecima sp. nov. was widely distributed in Japan during Early Pleistocene time. The species composition in the sample chosen as type suggests that the new fossil species occupied a brackish-water habitat. Differences in morphological features from closely related taxa are discussed.

Climate variation during the Holocene influenced the skeletal properties of Chamelea gallina shells in the North Adriatic Sea (Italy).

Understanding how marine taxa will respond to near-future climate changes is one of the main challenges for management of coastal ecosystem services. Ecological studies that investigate relationships between the environment and shell properties of commercially important marine species are commonly restricted to latitudinal gradients or small-scale laboratory experiments. This paper aimed to explore the variations in shell features and growth of the edible bivalve Chamelea gallina from the Holocene sedimentary succession to present-day thanatocoenosis of the Po Plain-Adriatic Sea system (Italy). Comparing the Holocene sub-fossil record to modern thanatocoenoses allowed obtaining an insight of shell variations dynamics on a millennial temporal scale. Five shoreface-related assemblages rich in C. gallina were considered: two from the Middle Holocene, when regional sea surface temperatures were higher than today, representing a possible analogue for the near-future global warming, one from the Late Holocene and two from the present-day. We investigated shell biometry and skeletal properties in relation to the valve length of C. gallina. Juveniles were found to be more porous than adults in all horizons. This suggested that C. gallina promoted an accelerated shell accretion with a higher porosity and lower density at the expense of mechanically fragile shells. A positive correlation between sea surface temperature and both micro-density and bulk density were found, with modern specimens being less dense, likely due to lower aragonite saturation state at lower temperature, which could ultimately increase the energetic costs of shell formation. Since no variation was observed in shell CaCO3 polymorphism (100% aragonite) or in compositional parameters among the analyzed horizons, the observed dynamics in skeletal parameters are likely not driven by a diagenetic recrystallization of the shell mineral phase. This study contributes to understand the response of C. gallina to climate-driven environmental shifts and offers insights for assessing anthropogenic impacts on this economic relevant species.

Broodstock conditioning, spawning, embryonic and early larval development of a novel baby clam species for aquaculture in the southeast Pacific: Tawera elliptica (Lamarck, 1818)

Tawera elliptica is a small size (baby) clam with an export fishery in southern Chile. The species is dioecious with external fertilization and without sexual dimorphism. The aim of this work was to optimize broodstock conditioning, induce spawning and describe embryonic development until the early larval stage in a hatchery. Broodstock were conditioned at 3 treatments (with/without sand; water circulation) for 48 days. The clams were fed with a mixed diet of macroalgae, with a daily ration of 250,000 cells/ml. Broodstock response was quantified using condition index and gonad development stages (histological techniques). For spawning induction, physical and biological methods were tested. The best response was achieved in males with physical induction. Histological analysis showed that the water circulation system treatment exhibited the highest percentage of maximum maturity. A fertilization ratio of 500:1 sperm:oocyte was used. The incubation was carried out in 3-L containers with filtered seawater at 10.7 ± 0.9°C without aeration. Observations, measurements and the duration of each embryonic and larval stage were recorded. The oocyte has a prominent gelatinous layer (= jelly coat) that disappears between the gastrula and trochophore stages. The status of the D-larval stage was reached at 107 h post fertilization with a mean valve length of 91.4 ± 8.9 µm. This is the first record of the complete embryonic development of this baby clam until the early larval stage and the conditioning in a water circulation system for 48 days are suitable for the species.

Optimal valve slide length for brass instruments

One of the first patents for compensating valve brass instruments by US Letters Patent #457,337 dated 11 August 1891 of Fontaine Besson is studied and optimized to obtain a much better in tune compensating instrument. The variance of intonation for the Besson instrument is 18.86%. An optimized four valve brass instruments is devised that lowers the variance to 4.22%. However, the first valve is flat by 7.39% on both sides of the instrument. Because intonation errors of ±5% are tolerable a spring loaded trigger must be provided to shorten the first valve when used alone. An EXCEL spreadsheet is presented analyzing many different three, four and five valve compensating and noncompensating instruments. Of particular interest is a five valve compensating instrument having a variance of 2.37% and standard deviation of 2.48%. The fifth valve lowers the instrument by 6 semitones. Instead of the fifth valve aforementioned a fifth valve of 0.237 of the length of the fourth valve could be used in combination with the fourth valve making the horn lighter. An Excel spread sheet is presented for the calculations relating to many ordinary and compensating three, four and five valve instruments.

Morphology and morphometric variations in Indian populations of Meloidogyne graminicola Golden and Birchfield, 1965

The study aimed at the morphological and morphometrical characterisation of eight populations of Meloidogyne graminicola from India. We studied different life stages, female, second-stage juveniles (J2s) and eggs of each M. graminicola population. Female characters such as stylet length, distance from the head-end to the median bulb, length and width of metacorpus valve were considered as stable characters. The distance between anus to vulval slit, and phasmid to the anus in perineal pattern showed the least variations. Similarly in body length, stylet length, and the ratio of c-value in J2s showed the least variations. This study noted two types of J2s; the short-form in Assam, Karnataka, Odisha, and West Bengal and the long-form in Haryana, Himachal Pradesh, Uttar Pradesh, and Tamil Nadu. They could be easily identified; the short form J2s is 410-480 µm and the long-form is 510-580 µm.