Condition Index Research Articles

Ocean Acidification and Sea Temperature Rise Affect the Queen Scallop Aequipecten opercularis (Linnaeus, 1758) in Captivity

Climate change poses risks to bivalves; thus, searching for resilient alternative species is crucial for sustainable fisheries. This study examines the impact of reduced pH and elevated temperature and their combined effects on the queen scallop Aequipecten opercularis in captivity. The results indicated that a low pH reduced its growth rates in both weight (0.03 ± 0.05 g/day) and length (0.06 ± 0.16 mm/day), as well as leading to decreases in meat yield (20.75 ± 2.75%) and the condition index (44.21 ± 7.19%). Conversely, elevated temperature resulted in an increased growth in length (0.07 ± 0.23 g/day), meat yield (21.57 ± 4.82%), and condition index (45.42 ± 7.35%). Combined stressors initially promoted growth but ultimately produced unsustainable outcomes, resulting in a reduced meat yield (18.28 ± 2.60%) and condition index (38.92 ± 8.23%), along with a peak mortality rate of 27%. These findings indicate that while A. opercularis can withstand individual stressors, exposure to simultaneous stressors may compromise its long-term viability in aquaculture systems.

Ranking of power grid facilities as a tool for choosing a repair management system

In the long-term planning of repairs at power grid facilities in conditions of limited operational and investment resources, it is important to determine the "points of maximum return", that is, the objects whose repair will cause the greatest effect in terms of the company's target priorities. This requires an operational assessment and ranking of electric grid facilities, taking into account the technological and resource characteristics of the energy company. The article presents a decision-making methodology that, based on operational calculations and priority assessment, enables to identify power grid facilities with the highest repair efficiency in the sense of criteria characterizing the strategic goals of asset management of an energy company. The methodology combines methods of modeling and calculating the probabilities of failure in consumer power supply systems (PSS) with the determination of indices of the technical condition of equipment, methods for calculating labor costs for maintaining and restoring reliability and assessing damage from its disruptions.The developed methodology allows the energy company — the owner of assets, when choosing the most effective repair management system according to enlarged indicators and simplified models, to form prioritization lists of objects for which the critical repair rank corresponds to its strategic priorities. The possibility of cost estimation of the total labor costs for the maintenance of facilities for each of the received prioritization lists in comparison with the repair fund stated by the energy company expands the scope of the methodology and increases the validity of the decisions made. The methodology has been verified and confirmed by consideration on the example of a real PSS of oil fields using up-to-date operational information.

Abstract Su704: Body Mass Index and Outcomes of In-Hospital Cardiac Arrest

Background: Although previous studies have reported an association between a patient’s body mass index (BMI) and outcomes for various cardiovascular conditions, the relationship between BMI and survival for in-hospital cardiac arrest (IHCA), a condition for which emergent response is required, has not been fully described. Aims: Examine the association between BMI and survival outcomes for IHCA. Methods: Within the Get With The Guidelines®-Resuscitation, we identified 56,411 patients with IHCA and available BMI data during 2005-2012 when weight and height data were collected in the registry. BMI was classified as underweight [<18.5 kg/m 2 ], normal [18.5 to 24.9 kg/m 2 ], overweight [25.0 to 29.9 kg/m 2 ], obese [30.0 to 34.9 kg/m 2 ], and very obese [≥35.0 kg/m 2 ]). Using multivariable hierarchical models with hospital as a random effect, we examined the association between BMI and survival to discharge, stratified by cardiac arrest rhythm type (shockable and non-shockable). As secondary outcomes, we examined rates of sustained return of spontaneous circulation for > 20 minutes (ROSC) and favorable neurological survival (i.e., survival to discharge without severe neurological disability). Results: Among 10,219 patients with a shockable arrest rhythm, 3,964 (38.7%) survived to discharge. After multivariable adjustment, compared with overweight patients, those who were underweight, of normal weight, and very obese had lower survival rates, whereas obese patients had similar survival rates ( Table ). Underweight patients also had a lower rate of ROSC and favorable neurologic survival ( Table ). Among 46,192 patients with a non-shockable arrest rhythm, 7,331 (15.8%) survived to discharge. After multivariable adjustment, all BMI groups had similar rates of survival, ROSC, and favorable neurologic survival, except for underweight patients ( Table ). Conclusions: Although the association between BMI and survival outcomes for IHCA varied by initial rhythm, underweight patients consistently had lower survival rates of survival. Very obese patients generally had similar outcomes to other weight groups, underscoring that morbid obesity was not a negative predictor of survival outcomes for IHCA.

Ecology and phenology of the bat tick Argas (Carios) dewae (Acari: Argasidae).

Although 12 soft tick species (Argasidae) are native to Australia, the ecology of most is poorly known. Argas dewae parasitizes several insectivorous bat species and has been recorded on humans. Therefore, understanding its ecology is crucial for wildlife health management and public health preparedness. To address this knowledge gap, A. dewae populations were monitored from 2 bat hosts (Chalinolobus gouldii and Austronomus australis) using bat boxes at 3 sites in Victoria, Australia, for 28 months (July 2005–December 2007). A phenological profile undertaken for A. dewae revealed that tick load on bat hosts increased throughout winter and peaked in the first month of spring, before collapsing and remaining low throughout the drier late spring and summer periods. There was also further investigation of the relationship between 2 response variables (tick infestation risk and tick load) and a range of explanatory variables (body condition index, sex, age class, bioseason, site, bat density per nest box). In C. gouldii, site was the only significant predictor of A. dewae infestation risk, while load was correlated with several variables including age class, sex, bioseason, roost density and body condition index. This paper also reports the first records of A. dewae from 6 bat species in 3 bat families (Miniopteridae: Miniopterus australis; Molossidae: A. australis; Vespertilionidae: Chalinolobus morio, Myotis Macropus, Vespadelus darlingtonia, Vespadelus regulus) and a second record of A. dewae from a human. The first distribution records are presented for A. dewae in South Australia, the Australian Capital Territory and Queensland.

Ultimate Fighting Crab: Agonistic Behaviour, Dominance, and Recognition in the Edible Crab, Cancer pagurus (L.)

Edible crabs (Cancer pagurus) are an economically important species for Scottish inshore fisheries, with an estimated annual landing value of GBP 16 million (2023). Research into the behaviour, particularly agonistic behaviour, of this species is currently lacking. This paper aims to investigate behaviour, social interactions, potential hierarchies, and the impact of claw size on the outcomes of agonistic interactions of male C. pagurus through behavioural trials and retrials. Crabs were semi-randomly assigned to pairs (based on allocated condition index rating) and introduced to one another in trial tanks. Each pair underwent two trials, 24 h apart (the “trial” and “retrial”). Analyses of video records of agonistic bouts revealed that 77% of retrials were won by the initial victors, with a significant decrease in fight time between trials and retrials. Fight time was not correlated with weapon size (claw length, height, and depth). There were no differences in weapon size of winners and losers of bouts. Winners exhibited a significantly higher frequency of aggressive and dominant behaviours (approach, aggressive contact, threat displays, and mounting), and losers exhibited higher frequencies of submissive behaviours (withdrawal, retracting limbs, and remaining motionless). These results suggest that individual behaviour may play more of a role in dominance than size or other morphometric characteristics.

Light spectrum effects on giant freshwater prawns, Macrobrachium rosenbergii: Larval development, survival and preferences

The objective of this study was to evaluate the influence of different light spectra on growth, development indices, survival and color preferences in Macrobrachium rosenbergii larvae. First (trial 1, 25 days), prawns (100 larvae/L) were randomly allocated to 30 cylindrical plastic containers (1 L). This trial was designed with five treatments (light spectra) and six replications: red light, blue light, green light and white light or absence of light (controls) in the 12:12 light:dark (LD) cycle. Next (trial 2), 30 groups of five larvae in two different development stages (VII and XI) were allocated to a system of compartments with different lights: white, red, blue or green. This system was connected by tubes to enable light spectra choices. Final weight, weight gain, consumption and metamorphosis significantly improved under the white light condition versus the other tested groups (p<0.05). Survival, the Larval Stage Index, the Larval Condition Index and final biomass clearly improved under the white light condition (p<0.05). Conversely, the red light and no light conditions obtained unsatisfactory results. White light was preferred in larvae stage VII (p<0.05), but this behavior changed to blue when prawns reached life stage XI (p<0.05). These findings suggest that white light may be the best choice to optimize larval growth and survival, while color preferences may vary with development stage.

Assessment of Soil Moisture in Vegetation Regions of Mu Us Sandy Land Using Several Aridity Indicators

Drought, a significant calamity in the natural domain, has extensive worldwide repercussions. Drought, primarily characterized by reduced soil moisture (SM), presents a significant risk to both the world environment and human existence. Various drought indicators have been suggested to accurately represent the changing pattern of SM. The study examines various indices related to the Drought Severity Index (DSI), Evaporation Stress Index(ESI), Vegetation Supply Water Index(VSWI), Temperature-Vegetation Dryness Index(TVDI), Temperature Vegetation Precipitation Dryness Index(TVPDI), Vegetation Health Index(VHI), and Temperature Condition Index (TCI). An evaluation was conducted to assess the effectiveness of seven drought indicators, such as DSI, ESI, TVPDI, VSWI, etc., in capturing the changes in SM in Mu Us Sandy Land. The research results indicated that DSI and ESI had the highest accuracy, while TVDI and VSWI showed relatively lower accuracy. However, their smaller fluctuations in the time series demonstrated stronger adaptability to different regions. Additionally, the delayed impact of aridity indices on soil moisture, variable attributes, temperature, and vegetation coverage in sandy land and grassland areas with low, medium, and high coverage all contributed to the effectiveness of the four aridity indices (DSI, ESI, VSWI, and TVPDI) in capturing the dynamics of soil moisture. The primary element that affects the effectiveness of TVDI is the divergence of the relationship curve between Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI), which is a kind of deterioration. This paper presents a very efficient approach for monitoring soil moisture dynamics in dry and semi-arid regions. It also analyzes the patterns of soil moisture changes, offering valuable scientific insights for environmental monitoring and ecological enhancement.

Drought Characterization Using Multiple Indices over the Abbay Basin, Ethiopia

Analyzing agricultural and hydrological drought at different timescales is essential for designing adaptation strategies. This study aimed to assess agricultural and hydrological drought in the Abbay Basin of Ethiopia by using multiple indices, namely the standardized precipitation index (SPI), standardized precipitation evapotranspiration index (SPEI), normalized difference vegetation index (NDVI), vegetation condition index (VCI), and drought severity index (DSI). Climate extremes were assessed over the Abbay Basin between 1981 and 2022. The results indicate that the years 1982 and 2014 were the most drought-prone, while the year 1988 was the wettest year in the Abbay Basin. The results revealed the presence of extremely dry and severely dry conditions, potentially impacting agricultural output in the region. Agricultural drought was identified during the main crop seasons (June to September). The VCI results indicated the presence of extremely wet and severely wet conditions. In 2012, 65% of the area was affected by extreme drought conditions, while nearly half of the Basin experienced extreme drought in 2013 and 2022. The DSI results indicated the occurrence of agricultural drought, although the spatial coverage of extreme dry conditions was lower than that of the other indices. In 2003, 78.49% of the Basin experienced moderate drought conditions, whereas severe drought affected 20% of the region. In 2010, about 90% of the Basin experienced moderate drought. This study provides valuable insights for agricultural communities, enabling them to mitigate the impact of drought on crop yields by utilizing different adaptation strategies. An adequate knowledge of agricultural and hydrological drought is essential for policymakers to assess the potential effects of drought on socioeconomic activities and to recognize the significance of implementing climate change adaptation measures.

Apex carnivores coping with metal(loid) pollution and oxidative stress: biological and environmental drivers of variation in kidney of European brown bear

Induction of oxidative stress and the associated lipid peroxidation is a prevalent mechanism through which certain metal(loid)s exert nephrotoxic effects in mammals. Research on the toxic impacts of metal(loid)s in free-ranging large mammals at high trophic positions is exceedingly rare, yet crucial for understanding environmental exposure scenarios relevant to both human and animal risk assessment. Renal cortex tissues (N=457) of free-ranging brown bears (Ursus arctos) from the Dinara-Pindos population sampled in Croatia were analysed herein for toxic metal(loid)s and the underlying biological and environmental drivers of variation, with their time trend monitored during the 2009-2022 period. In 28 individuals from the 2021-2022 period, we additionally investigated associations between metal(loid)s and oxidative stress and damage biomarkers in renal cortex cells. The principal generalized linear models used to approximate variations in biomarkers of oxidative stress and damage included non-essential As, Cd, Pb, Tl and U, and essential Co, Cu, Fe and Zn. Age class and season of sampling had no impact on biomarker levels, except for lipid peroxidation, LP (April ↑). Age, sex (females ↑), body condition index (↓) and season of sampling significantly influenced metal(loid)s levels. Non-specific mammalian thresholds were crossed for Cd and Pb toxicity in 1-16% and 2% of population, respectively. Renal levels of metal(loid) did not exhibit a clear trend over the 13-year period. The levels found in this study were higher than in sympatric carnivorous and herbivorous species, but in line with findings in ursids worldwide. Potential adverse health effects from environmental exposure in brown bears may arise from disruption of oxidative balance, as evidence clearly indicated associated changes in catalase activity (↑), glutathione content (↑), LP (↓), reactive oxygen species (↓), total antioxidant capacity (↑) in the renal cortex due to the presence of the most toxicologically relevant Cd and Pb.

AGRICULTURAL DROUGHT ANALYSIS BASED ON REMOTE SENSING: THE CASE OF AYDIN, TURKIYE

Agricultural drought is a phenomenon that arises when there is a deficiency of moisture in the soil, which has a detrimental impact on the productivity of agricultural crops. In Aydın, Turkey, particularly in the fertile Söke Plain region, agricultural drought is a major problem for farmers. The use of satellite data based on remote sensing and the indices derived from them allows for the timely and spatially detailed monitoring of vegetation health and moisture conditions over large areas. This enables the early detection and monitoring of agricultural drought. The present study evaluates the occurrence of agricultural drought in Aydın province between 1995 and 2020. For this purpose, satellite images captured by the Landsat 5 Thematic Mapper (TM) and Landsat 8 Operational Land Imager (OLI) in August 1995 and 2020 and land cover maps produced by the European Space Agency (ESA) at the same dates were utilized. The Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) indices were produced using Landsat satellite images. Then, the Vegetation Temperature Condition Index (VTCI) was obtained to detect agricultural drought. Finally, the relationship between the VTCI and land cover (LC) was evaluated, as well as the changes in the VTCI index between 1995 and 2020. The study found that agricultural drought increased with rising land surface temperature and declining NDVI values in Aydın province between 1995 and 2020.

Environmental factors regulating the population dynamics and reproductive strategy of freshwater mussel Parreysia corrugata in the Padma River, Bangladesh

Freshwater mussel Parreysia corrugata is an ecologically important species endemic to south-east Asia, which has been suffering from a dramatic decline in recent years. The present study investigated the population dynamics and reproductive strategy of P. corrugata in a changing climate of Bangladesh waters. Mussels were sampled monthly from January to December 2021 from the Padma River near the Rajshahi city of Bangladesh. A total of 809 specimens were collected with a sizes ranging from 36.07 to 101.41 mm shell length and 7.92–87.54 g weight, respectively. The mussels displayed a growth pattern characterized by negative allometry in body weight-shell length relationship. The asymptotic length (L∞) was 106.05 mm, the growth coefficient (K) was 0.370 per year, and the growth performance index (Φ′) was 3.58. The recruitment of P. corrugata was occurred throughout the year, with a peak during the month of February. The annual total mortality (Z) was 1.15, and natural mortality (M) and fishing mortality (F) were 0.61 and 0.54 per year, respectively. The exploitation level was E = 0.47 which indicates a state of under exploitation. Sex was identifiable throughout the study period and the sex ratio of the mussels did not differ significantly from the 1:1 (M: F) ratio ((χ2 = 15.80, P > 0.05). In terms of gonadal development, maturation, and spawning activity, both sexes had similar trends. Histology identified five gonad development stages for both male and female mussels: early developing, late developing, ripe, spawning, and spent. Monthly GSI data showed significant seasonal fluctuations with the highest GSI in April and it was sharply declined in May indicating the peak spawning of the mussels, which was in consistent with condition index and gonadal histology. All the physicochemical parameters showed significant variation except for pH. The most important factors explaining mussel body condition (b value) and reproductive strategies (GSI and CI) were water temperature, dissolved oxygen and water level. Although no known major threats of this species have been documented from Bangladesh, conservation measures could be adopted to protect the natural habitats of P. corrugata from adverse physicochemical and hydrological factors.

Reproductive biology of the rock oyster Striostrea prismatica in two populations of the Mexican Central Pacific

ABSTRACT The oyster Striostrea prismatica is a fishery-relevant species in the eastern tropical Pacific, particularly in the Mexican Central Pacific (MCP), and little is known about its reproductive cycle. Therefore, our study analysed gametogenesis, sex ratio, sexual maturity stages, shell height at first maturity, and condition index during 2014 and 2015 in El Tizate and La Victoria in the MCP. The sex ratio was significantly biased towards males at both sites, presumably due to ontogeny or fishing pressure. The highest condition index was observed between April and May in both years, while lower values were observed from September to December. The reproductive cycle in both sites was annual, with maturity and spawning from June to August and the degradation phase in August. The condition index showed a negative correlation with temperature and chlorophyll a in both sites: as a result, the period of maximum maturity and spawning coincided with the closure of the fishery in Mexico (June-August). Females had more significant shell height at first maturity than males at both sites, possibly associated with fishing pressure. The information from this study is a significant contribution, but it is necessary to extend the studies to populations further south and further north.

Utility Cut Impact Assessment and Fee Development Using Pavement Management System

The purpose of this study is to estimate any damage caused by utility cuts to pavements and develop a fee schedule to recover the costs associated with such damage using the City of Pacifica, CA, U.S.’s pavement management system (PMS). To accomplish this, the study looked at the functional deterioration of pavements resulting from utility cuts. The City of Pacifica’s PMS containing a vast dataset of pavement distress spanning 15 years, comprising thousands of data points encompassing various pavement ages and conditions, was analyzed to assess the impact of utility cuts. The findings from this study include: 1) Pavements with cuts of any size deteriorate more than pavements without cuts across all age groups with one exception for older residentials with small cuts; 2) On average, pavement condition index drops by 30% if the cut area is greater than 10% of the section area; and 3) Utility cuts inflict greater damage on newer pavements (&lt;10 years old) compared with older ones (≥10 years old). Consequently, new pavements experience an average percent reduction of approximately 33% in their remaining service life, while older pavements suffer a reduction of about 17%. The statistical analyses indicate that utility cuts caused significant damage, and supported a tiered utility cut fee structure based on functional classification, age of pavement, and size of the cut. The resulting fee schedule is based on 2021 material and construction cost estimates; consequently, implementation including an annual adjustment for inflation is recommended. Example fee calculations are provided.

EVALUATION OF THE AIRPORT PAVEMENT CONDITION INDEX IN THE AIRCRAFT LATERAL WANDER AREA

EVALUATION OF THE AIRPORT PAVEMENT CONDITION INDEX IN THE AIRCRAFT LATERAL WANDER AREA

Effects of Breeding Habitat on the Abundance and Body Condition of Two &lt;i&gt;Pelophylax&lt;/i&gt; Species in Agriculture and Urban Landscapes

Amphibians play a key role in structuring biological assemblages of agricultural landscapes, but they are threatened globally by agricultural intensification. Numerous studies have considered the morphology of animals to be an indicator of the health of a population, but data about the differences in amphibian morphology in different breeding habitats in agricultural landscapes are still missing. Here, we investigated the differences in the abundance and morphology of Pelophylax plancyi and Pelophylax nigromaculatus in the three waterbody types: fields, forests, and parks in agricultural landscapes in Nanjing, China. Our results emphasize that both frog species in forests and parks had significantly higher body condition indexes than those in fields, whereas their abundance in fields habitat was higher than those of the two other habitat types. Our results demonstrated the importance of non-agricultural habitats (such as forests and parks) in agricultural landscapes to the persistence of both Pelophylax species. We recommend preserving field ecosystems by constructing diverse waterbodies other than fields in rural areas and maintaining microhabitats in parks and forests to improve amphibian biodiversity in Nanjing.

The Spatiotemporal Variations in and Propagation of Meteorological, Agricultural, and Groundwater Droughts in Henan Province, China

As the global climate changes and droughts become more frequent, understanding the characteristics and propagation dynamics of drought is critical for monitoring and early warning. This study utilized the Standardized Precipitation Evapotranspiration Index (SPEI), Vegetation Condition Index (VCI), and Groundwater Drought Index (GDI) to identify meteorological drought (MD), agricultural drought (AD), and groundwater drought (GD), respectively. Sen’s slope method and Mann–Kendall trend analysis were used to examine drought trends. The Pearson correlation coefficient (PCC) and theory of run were utilized to identify the propagation times between different types of droughts. Cross-wavelet transform (XWT) and wavelet coherence (WTC) were applied to investigate the linkages among the three types of droughts. The results showed that, from 2004 to 2022, the average durations of MD, AD, and GD in Henan Province were 4.55, 8.70, and 29.03 months, respectively. MD and AD were gradually alleviated, while GD was exacerbated. The average propagation times for the different types of droughts were as follows: 6.1 months (MD-AD), 4.4 months (MD-GD), and 16.3 months (AD-GD). Drought propagation exhibited significant seasonality, being shorter in summer and autumn than in winter and spring, and there were close relationships among MD, AD, and GD. This study revealed the characteristics and propagation dynamics of different types of droughts in Henan Province, providing scientific references for alleviating regional droughts and promoting the sustainable development of agriculture and food production.

Combined Drought Index Using High-Resolution Hydrological Models and Explainable Artificial Intelligence Techniques in Türkiye

We developed a combined drought index to better monitor agricultural drought events. To develop the index, different combinations of the temperature condition index, precipitation condition index, vegetation condition index, soil moisture condition index, gross primary productivity, and normalized difference water index were used to obtain a single drought severity index. To obtain more effective results, a mesoscale hydrologic model was used to obtain soil moisture values. The SHapley Additive exPlanations (SHAP) algorithm was used to calculate the weights for the combined index. To provide input to the SHAP model, crop yield was predicted using a machine learning model, with the training set yielding a correlation coefficient (R) of 0.8, while the test set values were calculated to be 0.68. The representativeness of the new index in drought situations was compared with established indices, including the Standardized Precipitation-Evapotranspiration Index (SPEI) and the Self-Calibrated Palmer Drought Severity Index (scPDSI). The index showed the highest correlation with an R-value of 0.82, followed by the SPEI with 0.7 and scPDSI with 0.48. This study contributes a different perspective for effective detection of agricultural drought events. The integration of an increased volume of data from remote sensing systems with technological advances could facilitate the development of significantly more efficient agricultural drought monitoring systems.

Influence of Contaminants Mercury and PAHs on Somatic Indexes of the European Hake (Merluccius merluccius, L. 1758).

This research investigates the dynamics of contaminant exposure in European hake (Merluccius merluccius, L. 1758) from the Adriatic Sea (Central Mediterranean Sea) by examining the levels of total mercury (THg) and polycyclic aromatic hydrocarbons (PAHs) in the muscle fish tissues. The study explores the correlations between these pollutants and somatic indexes to identify the early warning signals of pollution and ecological effects. The levels of pollutants are influenced by season and sex. Lipids appear to have a minimal effect on the PAH levels, whereas they exhibit a positive correlation with mercury levels in the muscle. No significant relationships between the pollutants and condition indexes were observed, except for a positive correlation between THg and the gonadosomatic index, indicating a potential impact on the reproductive health of fish. In contrast, PAHs showed no meaningful correlation with condition indexes. Differences in contaminant accumulations and lipid levels between sexes reflect variations in metabolic activity, reproductive costs, and adaptive strategies to seasonal changes and energy demands. This study highlights the importance of long-term monitoring to improve pollution management, environmental conservation, and the protection of marine organisms' health.

Comparison of Condition Indices of Redheads From Different Wintering Areas

Abstract Redheads Aythya americana concentrate annually in traditional wintering areas along the Gulf of Mexico coast from Florida to Tamaulipas, Mexico. We collected 399 redheads during two winters (1988–1989 and 1989–1990) from four traditional wintering areas in the United States: Chandeleur Sound (Louisiana), Redfish Bay (Texas), upper Laguna Madre–Baffin Bay (Texas), and lower Laguna Madre (Texas). Salinity, water depth, and human disturbance differed among these locations. We used metrics of ingesta-free body mass, whole skin mass, flight muscle (breast muscle) mass, and leg muscle mass, all corrected for body size, as indices to compare body condition of birds among the four wintering areas. Ingesta-free body mass and whole skin mass were greatest in the Louisiana and Redfish Bay birds, whereas flight muscle mass was greatest in birds from the upper Laguna Madre–Baffin Bay location. Leg muscle mass was greatest in birds wintering in Louisiana. Mean leg muscle mass was the only measure that did not increase significantly over the winter in any location, and leg muscle mass decreased in birds from two locations (upper Laguna Madre–Baffin Bay and lower Laguna Madre). None of the body condition indices increased over winter for birds from the upper Laguna Madre–Baffin Bay. Our findings demonstrate that redhead body condition indices, and hence nutrient reserves, vary among population segments from different bay and lagoonal systems on the Gulf of Mexico winter range. Consequently, site-specific environmental conditions may affect physical condition and fitness of wintering birds. Specifically, hypersaline conditions, combined with boating disturbance, through their influence on energetic costs from flying, swimming, and osmotic regulation, may explain differences in redhead body condition indices during winter. Failure to consider these factors during development of harvest regulations could be consequential for waterfowl population management.

Economic Influences on Plantation Sector Stock Prices in Malaysia: A Quantile Regression Approach

This study aims to examine the relationship between microeconomic, sentiment, and macroeconomic variables across three quantiles (q25, q50, and q75) of stock prices in the Malaysian plantation sector. This study used Earnings per share (EPS) and return on equity (ROE) as the proxy for microeconomic variables, consumer sentiment index (CSI), and business condition index (BCI) as the proxy for sentiment variables, while inflation (INF which proxy from consumer price index) and exchange rate (ER, RM/USD) as the proxy for macroeconomic variables. Using a panel dataset covering 32 listed companies in plantation sector from 2008Q3 to 2023Q3. Result of quantile regression indicates that EPS, BCI, INF have a consistently positive and statistically significant relationship with stock prices across all quantiles. ROE has a mixed impact, with a positive relationship at the 25th and 50th quantile, but with a negative relationship at the 75th quantile. Furthermore, CSI and ER have a consistently negative and statistically significant relationship with stock prices across all quantiles.