Central Zone Research Articles

Study of corneal and retinal thicknesses at five years after FS-LASIK and SMILE for myopia

BackgroundThis study aimed to observe corneal and retinal thicknesses at 5 years after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) for myopia, investigate the effect of epithelial remodeling on refractive status and visual quality, and compare retinal thicknesses among fundus tessellation grades.MethodsPatients who received FS-LASIK or SMILE 5 years before were enrolled in this cross-sectional study. After 1:1 propensity score matching, each surgical group obtained 177 patients (177 eyes). Examinations including visual acuity, refraction, corneal and retinal thicknesses, corneal higher-order aberrations (HOAs), and fundus photography were performed in this visit at 5 years after surgery. The Quality of Vision (QoV) questionnaire was used to assess visual symptoms and overall satisfaction. Corneal and retinal thicknesses between groups were compared, contributing factors were analyzed, and correlations with postoperative refractive status, HOAs, QoV scores and overall satisfaction were evaluated.ResultsThe discrepancy of epithelial thickness between central and pericentral zones in FS-LASIK group was larger than that in SMILE group, which was negatively correlated with postoperative spherical equivalent (SE), positively correlated with spherical aberration (all P < 0.05), but not correlated with QoV scores and overall satisfaction (all P > 0.05) in both surgical groups. There was no statistical difference in stromal thickness and total corneal thickness (all P > 0.05). Most annuluses of epithelial and stromal thicknesse were linearly related to preoperative SE (all P < 0.05). The macular thickness, ganglion cell complex thickness, and retinal nerve fiber layer thickness exhibited comparable values between two surgical groups and four fundus tessellation grades, with no significant association observed with postoperative SE (all P > 0.05).ConclusionThe tendency that epithelial thickness in central zone was thicker than peripheral zone was more obvious at 5 years after FS-LASIK compared to SMILE. This uneven distribution of epithelial thickness might play a role in myopic regression and the changes in HOAs, especially in patients with high myopia, but it had little effect on patients’ subjective visual quality and satisfaction. Retinal thicknesses were not affected by these two surgical methods, and they did not appear to be the clinical indicators for myopic regression or fundus tessellation progression.

Performance Evaluation of Stress Tolerant Rice Variety Swarna Shreya under Front Line Demonstration in Bolangir District, Odisha

Rice is the major crop of Odisha with a total coverage of 41 lakh ha which is about 65% of the total cultivable area of the state. Area under rice crop in Bolangir district is 218.97 thousand ha. Bolangir District is located under Western Central Table Land Agro climatic Zone characterized by hot and sub humid climate. About 168.91 thousand ha rice is under rainfed condition. Drought is a major abiotic stress that adversely affects the rice growth, mostly in the rainfed ecosystem that ultimately affects the biomass production and yield. Front line demonstrations have been conducted in NICRA adopted village- Odiapali, Block- Bolangir in the Kharif season of the year 2022 and 2023. The percentage increase in yield is 13.63 and 14.61 and net return is Rs 42,200/- and Rs 43,444/- per ha as compared to farmer’s practice variety Swarna’ performance respectively for the year 2022 and 2023.

Laser powder bed fusion of Mg–Zn–Zr alloy: Formability, microstructure evolution and biodegradation behavior

Laser powder bed fusion (LPBF) was used to fabricate Mg–Zn–Zr (ZK60) parts, with a thorough investigation of processability by varying laser power and scanning rate. The combined effect of these parameters, which determines laser energy density, significantly impacted the forming quality of LPBF ZK60. Dense parts (over 99%) free of visible defects such as pores and cracks were achieved at a laser energy density of 74.1 J/mm2. The formation mechanisms of pores and cracks were extensively analyzed concerning the characteristics of the molten pool and subsequent cooling behavior. The LPBF ZK60 parts exhibited extremely fine grains, with an average grain size of 3.2 μm. Both equiaxed and columnar grains were observed, with a central equiaxed zone in the melt pool and a perpendicular lamellar zone along its boundary. Additionally, the Mg7Zn3 eutectic phase precipitated within the α-Mg matrix of ZK60. Immersion and electrochemical tests indicated that the XZ plane displayed superior corrosion resistance, attributed to fewer deformation regions and lower dislocation density. Furthermore, in vitro cell experiments confirmed that the ZK60 alloy possesses good biocompatibility.

Central molecular zones in galaxies: thirco (6-5) and molecular gas conditions in bright nearby galaxies

This paper summarizes all presently available $J_ upp thirco and accompanying co measurements of galaxy centers including new $J$=6-5 thirco and co observations of eleven galaxies with the Atacama Pathfinder EXperiment (APEX) telescope and also $Herschel$ high-$J$ measurements of both species in five galaxies. The observed $J$=6-5/$J$=1-0 co integrated temperature ratios range from 0.10 to 0.45 in matching beams. Multi-aperture data indicate that the emission of thirco (6-5) is more centrally concentrated than that of co (6-5). The intensities of co (6-5) suggest a correlation with those of $ but not with those of HCN. The new data are essential in refining and constraining the parameters of the observed galaxy center molecular gas in a simple two-phase model to approximate its complex multi-phase structure. In all galaxies except the Seyfert galaxy NGC 1068, high-$J$ emission from the center is dominated by a dense ($n and relatively cool (20-60 K) high-pressure gas. In contrast the low-$J$ lines are dominated by low-pressure gas of a moderate density ($n and more elevated temperature (60-150 K) in most galaxies. The three exceptions with significant high-pressure gas contributions to the low-$J$ emission are all associated with active central star formation.

Umbelliprenin attenuates comorbid behavioral disorders in acetic acid-induced colitis in mice: mechanistic insights into hippocampal oxidative stress and neuroinflammation.

Inflammatory bowel disease (IBD) is often accompanied by psychiatric disorders. Emerging evidence suggests that neuroinflammation and oxidative stress contribute to the psychiatric symptoms associated with IBD. Umbelliprenin (UMB) possesses several pharmacological properties, including anti-inflammatory and antioxidant effects. This study aimed to investigate the protective effects of UMB on comorbid behavioral disorders in a mouse model of experimental colitis, focusing on its potential anti-neuroinflammatory and antioxidant activities. After inducing colitis with acetic acid, male NMRI mice were treated for 7 consecutive days with UMB, saline, or dexamethasone. Behavioral assessments included the forced swimming test (FST), splash test, open field test (OFT), and elevated plus maze (EPM). Histopathological changes in the colon were evaluated, and total antioxidant capacity (TAC), malondialdehyde (MDA) levels, and the expression of inflammatory genes (TNFα, IL1β, and TLR4) were measured in the hippocampus. Colitis was associated with increased immobility time in the FST, reduced entries and time spent in the open arms of the EPM, decreased grooming behavior in the splash test, and reduced time spent in the central zone of the OFT. Colitis also resulted in a reduction in TAC and an increase in MDA levels and inflammatory gene expression in the hippocampus. UMB treatment mitigated the behavioral disorders associated with colitis, reduced neuroinflammation and oxidative stress in the hippocampus, and alleviated histopathological alterations in the colon. In conclusion, UMB may reduce behavioral disorders induced by colitis by decreasing oxidative stress and neuroinflammation in the hippocampus.

Prevalence of post-traumatic stress disorder and associated factors among police officers in Central Gondar Zone, North West Ethiopia, 2023: institutional-based cross-sectional study.

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that follows exposure to a traumatic or stressful life event. Police officers are exposed to a number of traumatic events that put them at risk of developing post-traumatic stress disorder. Previous studies have found the prevalence of post-traumatic stress disorder among police officers to be varied and inclusive. However, in Ethiopia, little is known about the prevalence of post-traumatic stress disorder and associated factors among police officers. Therefore, assessing the prevalence and associated factors of post-traumatic stress disorder among police officers might have a plausible role in future investigations. The aim of this study was to assess the prevalence of post-traumatic stress disorder and associated factors among police officers in Central Gondar Zone, North West Ethiopia, 2023. An institutional-based cross-sectional study was conducted in Central Gondar Zone by using self-administered and semi-structured questionnaires. A multi-stage cluster sampling technique was employed to select a sample of 634 participants. Post-traumatic stress disorder was assessed using the PTSD Checklist DSM-5. The collected data were coded and entered using Epi data Software version 4.6.02 and then exported to STATA version 14 for analysis. Bivariable and multivariable logistic regression analyses were done to identify factors associated with post-traumatic stress disorder. Statistically significant results were declared at a 95% confidence interval (CI) of a p-value less than 0.05. The prevalence of post-traumatic stress disorder was found to be 15.2%, with a 95% CI of 12.5% to 18.3%. In the multivariate analysis, female (AOR = 3.36, 95% CI 1.95-5.78), being directly exposed to traumatic events (AOR = 2.01, 95% CI 1.16-3.48), current alcohol use (AOR = 2.90, 95% CI 1.65-5.12), and having poor social support (AOR = 4.25, 95% CI 1.58-11.36) were factors significantly associated with post-traumatic stress disorder. According to this study, police officers suffered from a significant burden of post-traumatic stress disorder. Female sex, police personnel directly exposed to traumatic events, current alcohol users, and those who had poor social support were found to be strongly associated with post-traumatic stress disorder. Therefore, early detection and intervention are crucial to mitigating the overall problem.

Anisotropic mechanics of cell-elongated structures: Finite element study based on a 3D cellular model

Cell-elongated structures present designable anisotropic behaviors by controlling the ratio and angle of elongation, but the relationship between geometric anisotropy and mechanical anisotropy remains poorly understood. In this study, a construction method based on the 3D Voronoi technique is employed to generate cell-elongated structures with different elongation ratios and angles, and their anisotropic compression behaviors are investigated using a 3D cellular model. The stress–strain curves can be categorized into four stages, including elasticity, initial collapse followed by strain-softening, plateau, and densification, which are accurately described by a statistical constitutive model. Our finding reveals that the mechanical properties and deformation modes of the cell-elongated structures are significantly influenced by the anisotropic angle. At an anisotropic angle of 0°, randomly distributed collapse bands due to shell buckling interact with each other during compression, enhancing the load-carrying and energy-absorbing capacities. Conversely, at 90°, the cells deform primarily through a stable bending mode, leading to reduced stress and a lower Poisson’s ratio. At 45°, collapse bands appear on both sides of the sample with rotation and buckling being the dominant deformation mode, resulting in a sandwich-like structure featuring an uncollapsed central zone due to a combined compression–shear stress state. Compared with the isotropic foam, the structure elongated in thickness direction exhibits a notable increase in impact resistance under a spherical bullet. This work demonstrates the potential to engineer anisotropic cellular materials with tailored mechanical properties and deformation modes through strategic geometric anisotropy design.

Impacts of Electroconvulsive Therapy on the Neurometabolic Activity in a Mice Model of Depression: An Ex Vivo 1H-[13C]-NMR Spectroscopy Study

Electroconvulsive therapy (ECT) is an effective treatment for severe and drug-resistant depression, yet its mode of action remains poorly understood. This study aimed to evaluate the effects of ECT on neurometabolism using ex vivo 1H-[13C]-NMR spectroscopy in conjunction with intravenous infusion of [1,6-13C2]glucose in a chronic variable mild stress (CVMS) model of depression. Both CVMS and control mice were subjected to seven sessions of electroconvulsive shock under mild isoflurane anesthesia. The CVMS mice exhibited a reduction in sucrose preference (CVMS 67.1 ± 14.9%, n = 5; CON 86.5 ± 0.6%, n = 5; p = 0.007), and an increase in immobility duration (175.9 ± 22.6 vs. 92.0 ± 23.0 s, p &lt; 0.001) in the forced-swim test. The cerebral metabolic rates of glucose oxidation in glutamatergic (CMRGlc(Glu)) (CVMS 0.134 ± 0.015 µmol/g/min, n = 5; CON 0.201 ± 0.045 µmol/g/min, n = 5; padj = 0.04) and GABAergic neurons (CMRGlc(GABA)) (0.030 ± 0.002 vs. 0.046 ± 0.011 µmol/g/min, padj = 0.04) were reduced in the prefrontal cortex (PFC) of CVMS mice. ECT treatment in CVMS mice normalized sucrose preference [F(1,27) = 0.0024, p = 0.961] and immobility duration [F(1,28) = 0.434, p = 0.515], but not the time spent in the center zone (CVMS + ECT 10.4 ± 5.5 s, CON + sham 22.3 ± 11.4 s, padj = 0.0006) in the open field test. The ECT-treated CVMS mice exhibited reduced (padj = 0.021) CMRGlc(Glu) in PFC (0.169 ± 0.026 µmol/g/min, n = 8) when compared with CVMS mice, which underwent the sham procedure (0.226 ± 0.030 µmol/g/min, n = 8). These observations are consistent with ECT’s anticonvulsant hypothesis for its anti-depressive action.

Climate change impact assessment of growing degree days and thermal growing period of cotton in north-west India

ABSTRACT Temperature is an indispensable necessity of plant growth, which explains the 95% variability in plant development. Accumulated temperature, i.e. growing degree day (GDD) is a useful agro-climatic indicator that translates raw climatic data into meaningful decisions. In this study, the GDD concept is used to analyze spatio-temporal variability of accumulated growing degree days (AGDD) and thermal growing period of cotton for the past and future climates in the three different zones (north-east, central and south-west) of Punjab. During the baseline period, higher AGDD were accumulated in the south-western (2,441 °C day), followed by central (2,276.8 °C day) and north-eastern (2,073.8 °C day) zones. During the end of mid-century, AGDD of the central zone was increased by 4–11%, 3–27% for north-eastern, and 3–7% for south-western zones in contrast to the baseline period. This increase in AGDD of cotton might decrease the thermal growing period by 6–14%, 8–25%, and 4–8% for central, north-east and south-western zones, clearly indicating the thermal stress over the cotton crop. This study provides quantitative information for crop breeders and cotton scientists to develop new genetically modified cultivars and improved agronomic practices to mitigate the adverse effect of climate change.

An ALCHEMI inspection of sulphur-bearing species towards the central molecular zone of NGC 253

Context. Sulphur-bearing species are detected in various environments within Galactic star-forming regions and are particularly abundant in the gas phase of outflow and shocked regions in addition to photo-dissociation regions. Thanks to the powerful capabilities of millimetre interferometers, studying sulphur-bearing species and their region of emission in various extreme extra-galactic environments (e.g. starburst and active galactic nuclei) and at a high-angular resolution and sensitivity is now possible. Aims. In this work, we aim to investigate the nature of the emission from the most common sulphur-bearing species observable at millimetre wavelengths towards the nuclear starburst of the nearby galaxy NGC 253. We intend to understand which type of regions are probed by sulphur-bearing species and which process(es) dominate(s) the release of sulphur into the gas phase. Methods. We used the high-angular resolution (1.6″ or ∼27 pc) observations from the ALCHEMI ALMA Large Program to image several sulphur-bearing species towards the central molecular zone (CMZ) of NGC 253. We performed local thermodynamic equilibrium (LTE) and non-LTE large velocity gradient (LVG) analyses to derive the physical conditions of the gas where the sulphur-bearing species are emitted, and their abundance ratios across the CMZ. Finally, we compared our results with previous ALCHEMI studies and a few selected Galactic environments. Results. To reproduce the observations, we modelled two gas components for most of the sulphur-bearing species investigated in this work. We found that not all sulphur-bearing species trace the same type of gas: strong evidence indicates that H2S and part of the emission of OCS, H2CS, and SO are tracing shocks, whilst part of SO and CS emission rather traces the dense molecular gas. For some species, such as CCS and SO2, we could not firmly conclude on their origin of emission. Conclusions. The present analysis indicates that the emission from most sulphur-bearing species throughout the CMZ is likely dominated by shocks associated with ongoing star formation. In the inner part of the CMZ where the presence of super star clusters was previously indicated, we could not distinguish between shocks or thermal evaporation as the main process releasing the S-bearing species.

Sugar profile and sensory properties of honey from different geographical zones and botanical origins in Tanzania

Honey composition and sensory properties depend greatly on its botanical and geographical origins. In this study, the sugar profile and sensory properties of honey samples from different geographical zones and botanical origins in Tanzania were investigated. Thirty-two samples (3 zones x 2 origins x 4 samples) + (2 zones × 1 origin x 4 samples) were collected from the seven regions in five zones as follows; Simiyu (lake zone), Tabora and Dodoma (central zone), Manyara (northern zone), Morogoro (eastern zone), and Kigoma and Katavi (western zone) and evaluated for sugar profile and sensory properties using standards methods. Honey samples were primarily composed of fructose (39.5–47 g/100 g), glucose (32.0–35.0 g/100 g) and a small amount of sucrose (5.1 ± 0.50–7.3 ± 0.7 g/100 g). The total sugar ranged from 72.6 to 75.8 g/100 g/100g. The variations in sugar contents between zones and botanical origin were significant (p < 0.05) except for glucose. Sample from miombo origin in the lake and eastern zones had the highest fructose value (41.9 ± 0.8–42.04 ± 4.34 g/100 g) compared to lowest values (39.5 ± 2.17 g/100g) in a western zone while northern and lake zones had significantly (p < 0.05) highest and lowest sucrose values respectively. In all zones, acacia samples had higher fructose and sucrose contents than their miombo counterparts. As for the sensory profile, miombo samples in the western zone had significantly (p < 0.05) higher colour (8.0 ± 0.64) and aroma (7.5 ± 1.09) intensities while the lake zone samples had higher clarity (6.9 ± 1.76) than other zones’ samples. The findings have demonstrated that the geographical and botanical origins have a significant impact on the sugar profile and sensory profile of Tanzania honey. However, despite the variations, the consumption of honey from these zones and origins should be encouraged in light of their nutritional and related known health benefits.

Atención de urgencia por ideación suicida en Chile, periodo 2020 al 2022

IntroductionSuicidal ideation is a common risk factor associated with suicide and an important indicator for its prevention. The objective of this study is to describe the rate of emergency care for suicidal ideation in the population served in the Chilean public health network during the years 2020 to 2022. MethodsDescriptive study, based on records from the Department of Statistics and Health Information, of beneficiaries with emergency care for suicidal ideation. The rate of emergency care for suicidal ideation was estimated at the country and geographic region level, as well as with regards to the proportion of care by age group, type of health facility and month of occurrence. Pearson's Chi2 test was applied in STATA version 14. ResultsThere were 15,325 emergency visits for suicidal ideation in the period studied. In 2020, the rate was 0.03×10,000 and 5.8×10,000 in 2022, higher in the central zone. Care predominated in the 15 to 64 year-old group and in hospital settings (p<0.001). ConclusionsAn increase in the rate of emergency care for suicidal ideation is observed, with differences by age group and type of health facility. However, given the limited study time, these figures should be analyzed with caution.

Focal point technology: Controlling treatment depth and pattern of skin injury by a novel highly focused laser

Selective photothermolysis has limitations in efficacy and safety for dermal targets. We describe a novel concept using scanned focused laser microbeams for precise control of dermal depth and pattern of injury, using a 1550nm laser that generates an array of conical thermal zones while minimizing injury to the epidermis. To characterize the conical thermal zones invivo and determine safe starting parameters to transition to a second phase to explore potential clinical indications. A focused toroidal (ring) laser beam was delivered through a cold sapphire window, sparing epidermal injury in a central zone. Pulse energy, lesion depth, density, and energy delivery were titrated in exvivo human skin and subsequently on the backs of 21 human subjects. Histology showed microscale patterns of thermal injury, which varied predictably with laser parameters. Time-course healing through histology and skin surface imaging demonstrated the ability of the device to deliver high energies without sequelae. Clinical data are currently being collected to further explore the safety and efficacy of the device. The 1550nm laser with focal point technology enables precise control of lesion depth while simultaneously sparing a large portion of the epidermis, lowering the risk of adverse effects.

Bt cotton based cropping systems suitable for Central Vidarbha zone of Maharashtra

Bt cotton based cropping systems suitable for Central Vidarbha zone of Maharashtra

Evaluating the Effectiveness of Dramatic Approaches in Improving Oral Communication Skills among Arabic Language Students of Colleges of Education in North Central Zone Nigeria

Recent literature highlights a widespread issue of poor oral competence and communication skills among Arabic language students in Nigerian institutions of higher learning. Contributing factors, including the use of inappropriate teaching methods, have been identified. This study explores the impact of using drama techniques to enhance Arabic oral communication skills among students in Colleges of Education across North Central Nigeria. A pre-experimental design was utilized, with one group serving as the experimental group and the other as the control group. The intervention took place during the second semester of the 2023/2024 academic year, involving 51 students in their 200 level. The sample was divided into 26 students for the experimental group and 25 for the control group. To measure outcomes, a test and evaluation scale for oral expression skills was developed. Statistical analysis, including means, standard deviations, and independent sample t-tests, were applied. The findings indicated a statistically significant difference in favour of the experimental group, suggesting that drama techniques can be an effective approach for improving spoken Arabic, particularly within the Nigerian educational context

Species diversity of Molluscan fauna of Madhav National Park, Madhya Pradesh, India

The present study is based on the Molluscs samples present in National Zoological collection of Central Zone Regional centre, Zoological Survey of India, Jabalpur and the available Literatures. The Samples were collected back in the year from 1970 to 2017 by different tour parties surveying Madhav National Park and its vicinity over the years. The current study reveals the occurrence of 21 species of freshwater and Land mollusks belonging to 18 genera, 10 families, 7 orders of 2 classes of Phylum Mollusca. This is the first report of the mollusks species from this area which will help in evaluate the mollusks diversity of Madhav NP, Shivpuri.

Nutritional Imbalance between Omega-6 and Omega-3 Polyunsaturated Fatty Acids during Pregnancy Increases the Number of Pyramidal Neurons in the Basolateral Amygdala and Anxiety-Related Behavior in Offspring.

Modern agriculture allows for the production of foods that are high in n-6 linoleic acid and low in n-3 α-linolenic acid (LAhigh/ALAlow), which are suggested to be associated with an increased risk for the onset of anxiety disorders. However, there is not sufficient evidence to understand its underlying brain mechanism. Given that mouse offspring derived from mothers fed a LAhigh/ALAlow diet during gestation and early lactation showed increased anxiety-related behaviors and that rodents exposed to a LAhigh/ALAlow diet are more vulnerable to stress, in this study, we investigated the effects of maternal LAhigh/ALAlow diet consumption on stress-induced anxiety-related behavior and the brain structures involved in the expression of negative emotional states in mouse offspring. In a standard environment, offspring exposed to either the control diet or the LAhigh/ALAlow diet in utero showed similar stay times in the center zone in the open field test. On the other hand, under stressful environments, offspring exposed to the LAhigh/ALAlow diet in utero showed decreased stay times in the center zone compared to those exposed to the control diet. We further found that the number of a subpopulation of pyramidal neurons in the basolateral amygdala, which can regulate negative emotional behaviors, was greater in the offspring exposed to the LAhigh/ALAlow diet compared to those exposed to the control diet. These data suggest that maternal dietary imbalance between n-6 and n-3 polyunsaturated fatty acids confers stress vulnerability to offspring during the process of brain development.

A simulation study of the impacts of micro-hub scenarios for city logistics in Rotterdam

Micro-hubs are considered to be a potential solution to increase the consolidation of inner-city deliveries: in the City of Rotterdam it is a potential measure to increase the logistic efficiency in and around the planned zero-emission zone in the city center. When designing the configuration of micro-hubs in an urban setting multiple aspects should be considered, such as their location, the type of vehicles to operate them, and the business model to be adopted for their operation. And although the topic is much studied it remains difficult to predict how different micro-hub configurations affect the transportation system in terms of transport movements, number of travelled kilometers, etc. This paper describes the use of the Tactical Freight Simulator (TFS) to investigate the impact of micro-hubs on the transportation system in case they would be implemented at a wider scale across the city center, and make a comparison with the current state of last-mile delivery. The case study explores three different design aspects: location, type of vehicles (delivery robots, cargo bike, LEV), and the business model (individual/full collaboration). Results show that the largest reduction of vehicle kilometers can be achieved in the scenarios with full collaboration between the CEPs.

Exploring impact of green finance and natural resources on eco-efficiency: case of China

China ranks 160 out of 180 countries in terms of ecological efficiency, with an EPI score of 28.40 and a 10-year average change in score of 11.40. This article examines the impact of green finance and China’s natural resources on regional ecological efficiency using the Tobit regression model. The study uses the average yearly exchange rate to normalize dollar-related values and GDP to 2012 RMB using the price deflator. Variables used as explanatory tools include green financing, the availability of natural resources, and regional eco-efficiency. The results of the study imply that natural resources in eastern region of China are better managed as and have avoided the resource curse as compared to central and western regions. Resources temporarily support area economic and social growth. However, resource agglomeration locks many elements in the resource industry and degrades regional industrial development, generating environmental and social difficulties that may hinder regional economic progress. Given that Foreign Direct Investment (FDI) increases regional eco-efficiency after accounting for adjustment. The FDI positively correlated with ecological efficiency in the east zone, while central and western zones have negative correlations. The industrial development of the nation negatively impacts ecological efficiency in the East, Midwest, and West regions. Western results are distinctive, with ecological efficiency and regional economic growth frequently going hand in hand.

Calcareous nannofossil and U-Pb zircon geochronological data on the Coniacian–Santonian in a part of the Central Srednogorie Zone (central South Bulgaria)

The calcareous nannofossil assemblages in three sections (Dalgi Rid, Milkova Cheshma and Toplika) of the clayey-carbonate Mirkovo Formation in the Central Srednogorie Zone have been investigated. These sections were specifically chosen because, at their basal parts, they contain silica-manganese (± iron) mineralisations, which, according to recent studies, may prove useful for investigations into their potential as a source of ore and critical elements. The nannofloras exhibit very poor preservation and comparatively-low taxonomic diversity. Nevertheless, the presence of some biostratigraphically-significant taxa has been detected. Micula staurophora occurs consistently in sections Dalgi Rid and Milkova Cheshma, which, in the absence of Lithastrinus grillii, indicates the middle to late Coniacian UC10. The latter species was recognised, with a relatively-consistent stratigraphical range, in section Toplika. Although Lithastrinus septenarius and Arkhangelskiella cymbiformis are absent at Toplika, the studied sediments could not confidently be assigned solely to UC12, and thus a tentative late Coniacian (pars.)–Santonian (pars.) age was adopted for the strata in this section. This is consistent with the obtained LA-ICP-MS U-Pb age (86.2±1.4 Ma) of the youngest zircons from the volcaniclastics in the uppermost part of the Chelopech Formation at the same locality, immediately below the boundary with the overlying Mirkovo Formation.