Respiratory Water Research Articles

Effect of terracotta drinker and/or water addition of ASPRO‐C plus on behavior, growth, and physiological response of broiler chickens exposed to high temperature

AbstractThis study aimed to evaluate the effects of a terracotta drinker and/or water supplementation with ASPRO‐C Plus on the zootechnical performance of broiler chickens reared in a hot environment. A total of 160 Cobb 500 broiler chicks of 15 days old (240.2 ± 39.82 g) were divided into four treatment groups in a 2 x 2 factorial arrangement of drinker type (plastic or terracotta) and water with or without ASPRO‐C Plus (1 g/L) supplementation, each consisting of 4 replicate pens. Respiratory rate, water intake, feed intake, and live body weight were recorded weekly. At 49 days old, 12 birds per group were randomly selected, fasted for 12 h, weighed, and slaughtered for carcass evaluation and blood collection. The respiration rate of broilers decreased significantly (p < 0.01) with the terracotta drinker as compared to the plastic drinker. The water intake, the feed intake and the body weight gain increased significantly (p < 0.01) with the terracotta drinker as compared to the plastic drinker. The water addition of ASPRO‐C Plus significantly increased (p < 0.01) the relative weight of abdominal fat and spleen in broilers. The alpha‐amylase activity was significantly decreased (p < 0.01) with the water addition of ASPRO‐C Plus. The serum content of total cholesterol was significantly increased (p < 0.01) with the terracotta drinker. It can be concluded that ASPRO‐C Plus can slightly improve liveability, but using the terracotta drinker can be more efficient in reducing the behavioral response to heat stress and can improve the growth performance.

Comparing the Contributions of Cutaneous and Respiratory Evaporative Water Loss to Cooling in Anna’s Hummingbirds (Calypte anna) Under Fasted and Fed Conditions

During high-temperature periods, endothermic animals evaporate water from the body surface to cool down. The two primary routes of evaporative water loss are: (1) evaporating water from the skin; and (2) evaporation from the respiratory surfaces during breathing and panting. In smaller avian species like Anna's hummingbirds ( Calypte anna), the higher cutaneous surface area to volume ratio presents an opportunity for the skin to become an important avenue for evaporative cooling, possibly becoming a major site. Additionally, hummingbirds feed on water-rich nectar. As a result, they eliminate surplus water through urination, but significant evaporation can also occur through their skin and respiratory system. Thus, total evaporative water loss could rise significantly for these animals when in a hydrated state. Here, this study investigates the relative importance of the two evaporative water loss routes (cutaneous and respiratory) of Anna's hummingbirds in fed and fasted states. We hypothesize that cutaneous evaporation has a high contribution to total evaporation. Moreover, we predict that evaporative water loss rates are higher under the fed (hydrated) condition relative to fasted states. Metabolic and evaporation rates from the head and the body were measured separately in a partitioned chamber at 30°C. Birds were fed immediately prior to entry into respirometry, and the transition from fed to fasted states was recorded over a two-hour period. Total evaporative water loss nearly doubled in the fed versus fasted condition (1.75 ± 0.85 mg H2O/min and 0.97 ± 0.28 mg H2O/min, respectively), with respiratory water loss being significantly higher in the fed compared to the fasted condition (0.87 ± 0.38 mg H2O/min versus 0.42 ± 0.12 mg H2O/min, respectively). On the other hand, the body had a large, but non-significant, difference in evaporative water loss rates between the fed and fasted conditions (0.88 ± 0.55 mg H2O/min and 0.57 ± 0.17 mg H2O/min, respectively). Importantly, cutaneous evaporative water loss made up half of the total evaporation in both the fed and fasted conditions. These results demonstrate that evaporative water loss is modulated by hydration status at both the respiratory and cutaneous surfaces. Furthermore, cutaneous evaporation makes up approximately the same proportion of total evaporation to other birds at thermoneutral temperatures. Future work manipulating ambient temperature in conjunction with hydration status will further our understanding of the relative importance of cutaneous evaporation for these small-bodied birds. Funded by the Genentech Foundations Scholarship, CSUPERB New Investigator Grant, and San Francisco State University. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Some features of the perioperative management of patients with a tumor of the chiasmal cellaric region: a review

INTRODUCTION: Tumors of the chiasmal-sellar region (CSR) account for more than 20 % of all primary intracranial neoplasms, of which pituitary adenomas account for up to 20 % of the world population. Currently, removal of these neoplasms is performed using endoscopic transsphenoidal surgical accesses. OBJECTIVE: analysis of the results of publications concerning perioperative management of patients with CSO tumors. MATERIAL AND METHODS: publications were searched and selected in bibliographic databases PubMed, Web of Science, Scopus. To study the approach to perioperative management of patients with CSF tumors, the works published from 2013 to 2023 were analyzed. Search keywords: pituitary surgery, anesthesia. Based on the analysis of current problems in anesthesia planning for patients with CSF tumors, the search was expanded with additional keywords: “pituitary tumor”, “perioperative complications”, “endocrine disorders”, “difficult airway”, “acromegaly”, “cardiologic complications, acromegaly”, “peripheral neuropathy, acromegaly”, “trigemino-cardiac reflex”, 206 publications were additionally analyzed and the main key points in anesthesia planning were summarized. A total of 230 publications were included but 161 were excluded. A total of 69 studies were selected. RESULTS: The main features of patients with CSF tumors are: water-electrolyte disorders, cardiovascular pathology, difficult airway. This determines a multidisciplinary approach in preparation for surgery. It is necessary to take into account these features when planning anesthetic support and management of the early postoperative period. In addition, endoscopic transnasal-transsphenoidal access may cause a number of complications: damage to the hypothalamic region and large vessels, and in the postoperative period: respiratory disorders, hormonal insufficiency, Water and Sodium Disturbances. CONCLUSIONS: Additional vigilance is required when preparing a patient with CSF formation for surgery. Perioperative management of a patient with CSO tumor requires a team approach with participation of neurosurgeons, neurologists, ophthalmologists, endocrinologists, cardiologists, anesthesiologists-resuscitators.

Simulated logistical transport effects on textural change of wax apple using different packaging types during storage time

The textural damage caused by logistics transport is a major problem during the post-harvest logistics and storage time of agricultural products. To address the issue, this study investigated the impact on the textural change of wax apple with different packaging types by conducting international safe transit association 6-amazon. com-sioc type A (ISTA 6 A) tests and measured the changes in related indicators over the eight-day storage time period at 15 ℃. The results demonstrated that compared to non-vibrated wax apple of the same packaging type, the damage index of the vibration-treated wax apple increased to 0.39 at the end of storage time. This led to more noticeable damage to fruit texture in the vibration-treated wax apple. With the same outer packaging type, different types of expanded polyethylene (EPE) cushioning materials presented varying degrees of textural damage following vibration treatment. The order was double-layer foam net (DL-FN, 0.23) < single-layer foam net (SL-FN, 0.38) < EPE liner (EPE-L, 0.50). The superior cushioning performance of DL-FN could distribute vibratory energy across the entire wax apple to reduce partial textural injury, but SL-FN provided weaker cushioning protection. Furthermore, it was more beneficial for the dissipation of respiratory heat to suppress the related cell-wall enzymes activities and prevented internal cottony softening of wax apple by maintaining an appropriate environment within the packaging, while EPE-L prevented respiratory heat dissipation and water diffusion. Using the same cushioning type, no significant difference was observed in the damage of fruit texture between the wax apple packaging by foam box (FB, 0.25) and corrugated box (CB, 0.23). The finding suggested that when the outer package had sufficient supporting performance, the cushioning type required not only adequate cushioning property, but also excellent vapor and gas permeability in order to facilitate respiratory heat diffusion and better protect the textural integrity of the wax apple in the process of logistics. This protection was crucial for the development of wax apple in e-commerce logistics.

A Superhydrophobicity-Slipperiness Switchable Surface with Magneto- and Thermo-responsive Wires for Repelling Complex Droplets.

The inefficacy of repelling water droplets laden with macromolecules (complex droplets or diluted polymer solution) is a long-standing shortcoming of superhydrophobic surfaces, which severely limits their reliability in practical applications. Here, we design a surface termed the superhydrophobicity-slipperiness switchable surface (3S surface), which demonstrates superhydrophobicity at room temperature and slipperiness when heated. The 3S surface is composed of magneto-responsive wires coated with superhydrophobic nanoparticles and impregnated with thermoresponsive paraffin, exhibiting lotus leaf-inspired passive water repellency and respiratory cilia-inspired active water repellency at room temperature. When heated, the impregnated paraffin melts and forms a lubricant layer atop the surface structures, exhibiting the pitcher-plant-inspired removal of complex droplets that remain pinned on conventional superhydrophobic surfaces. The counterintuitive integration of superhydrophobicity (a liquid-solid-gas composite system) and slipperiness (a liquid-lubricant-gas system) into a surface and the on-demand switch between them are not only important to the applicability of self-cleaning surfaces to real-world environments, where complex liquids are inevitable, but also provide insights into various interface-related applications.

Effect of novel edible coating formulations on post-harvest quality of Chilli (Capsicum annuum var. Pusa Jwala): A review

Chilli (Capsicum annuum L.) holds a prominent position as a key spice crop, being widely utilized globally. Despite its agricultural significance, chilli is characterized by high moisture content (60–85%) at harvest, necessitating reduction to 8-12% for prolonged storage in a dehydrated form. However, it remains highly perishable, with a short shelf life and susceptibility to postharvest challenges such as fungal diseases, quality degradation, chilling injury, and rapid weight loss. Edible coatings have emerged as a solution to extend the postharvest shelf life of fruits and vegetables, enhancing mechanical handling properties and acting as a barrier to respiratory gases and water vapor. The possibility of hydrocolloid gums, such as gum arabic, as edible coatings has drawn interest. The purpose of this study is to determine whether an edible coating based on gum arabic (GA) can effectively preserve the quality of chiles when stored at room temperature. The goal of the research is to extend the storage life of chiles while improving their physiological and microbiological quality. A composite chitosan – gelatin (CH–GL) edible covering will be used to accomplish this. The effects of pure chitosan, cassava starch, gum arabica, and gelatin coatings on chillies will also be investigated in this study. In order to improve the marketability and resilience of chilli and possibly other horticultural commodities, the research aims to offer insights into the development of efficient and sustainable postharvest strategies by methodically evaluating the effects of these coatings on weight loss, firmness, colour retention, and nutritional content.

Effects of temperature and relative humidity on behavior and physiological indices in goats

High temperature and relative humidity (RH) affect the production and health of livestock. This study aimed to investigate the change rule of behavior and internal physiological status of goats under heat stress and determine the relationship between these factors. Eight 18-month-old female goats (non-pregnant or non-lactating) were randomly assigned to two environmental control chambers (labeled A and B; n = 4 per in each batch). Four temperatures (26 °C, 30 °C, 34 °C, and 38 °C) and four RH levels (35%, 5 0%, 65%, and 80%) were applied according to a 4 × 4 experimental design to establish a normal control (23 °C, 50%) and the experimental treatments. The duration of each treatment was five days. The behaviors of the goats were monitored in the first two days, the physiological indices were measured, and serum was collected within 3–5 d. The respiratory rate and HSP70 mRNA expression significantly increased at 74.8 < temperature-humidity index (THI) < 76.51; T3 significantly decreased at 80.62 < THI < 82.92; and the behaviors related to metabolism also significantly decreased at 85.24 < THI < 88.74 (including heart rate and rumination). However, the behaviors related to vapor cooling (including respiratory rate, water intake and urination) showed an opposite trend at this stage. In addition, heat stress disrupted the balance of interleukin-2 (IL-2)/interleukin-4 (IL-4). These findings provide a reference for designing suitable environments for goat breeding.

Increased dietary vitamin D3 and calcium partially alleviate heat stress symptoms and inflammation in lactating Holstein cows independent of dietary concentrations of vitamin E and selenium

Twelve multiparous Holstein cows (42.2 ± 5.6 kg of milk/d; 83 ± 27 d in milk) were used in a split-plot design testing the effects of mineral and vitamin supplementation on the time course of animal performance, metabolism, and inflammation markers during heat stress. The main plot was the average concentrations of dietary vitamin E and Se (adequate: 11.1 IU/kg of vitamin E and 0.55 mg/kg of Se, and high: 223 IU/kg of vitamin E and 1.8 mg/kg of Se, respectively). Within each plot, cows were randomly assigned to (1) heat stress (HS) with adequate concentrations of vitamin D3 and Ca (1,012 IU/kg and 0.73%, respectively), (2) HS with high concentrations of vitamin D3 and Ca (HS+D3/Ca; 3,764 IU/kg and 0.97%, respectively), or (3) pair-feeding (PF) in thermoneutrality with adequate concentrations of vitamin D3 and Ca (1,012 IU/kg and 0.73% Ca) in a Latin square design with 14-d periods and 7-d washouts. The highest rectal temperature was recorded at 1700 h for HS (39.4°C; mean of d 1 to 14), being 1.2 and 0.8°C greater than for PF and HS+D3/Ca, respectively. Respiratory rate and water intake were higher in HS (73 breaths/min and 115 L/d, respectively) relative to PF (28 breaths/min and 76 L/d). Heat stress decreased dry matter intake progressively, reaching a nadir on d 5 to 7 (33% reduction) and was not different between treatments. Milk yield decreased progressively in all treatments, but remained greater in PF relative to HS from d 3 to 14 (10%), whereas HS and HS+D3/Ca were not different. Milk fat, protein, and lactose concentrations and yields were lower in HS relative to PF from d 3 to 14, but not different between HS and HS+D3/Ca. Relative to PF, preprandial insulin concentrations were increased in HS, whereas plasma nonesterified fatty acids were decreased on d 7 and 14. Plasma lipopolysaccharide-binding protein concentrations increased in HS cows on d 7 and 14, respectively, relative to PF, whereas they were reduced in HS + D3/Ca on d 14. Plasma C-reactive protein, tumor necrosis factor-α, and fecal calprotectin were increased in HS relative to both PF and HS+D3/Ca on d 7 and 14. Rectal temperature was positively associated with plasma lipopolysaccharide-binding protein (r = 0.72), tumor necrosis factor-α (r = 0.74), C-reactive protein (r = 0.87), and with milk somatic cells (r = 0.75). Plasma 8-hydroxy-2-deoxyguanosine concentrations presented a 3-way interaction, where 8-hydroxy-2-deoxyguanosine was lower in HS than in PF on d 7 and 14, and lower in HS+D3/Ca relative to HS on d 14 in the adequate vitamin E and Se treatment, but no effects were observed in the high vitamin E and Se group. Plasma superoxide dismutase concentrations increased over time, and were higher in HS relative to PF on d 14, whereas HS+D3/Ca was similar to HS. Heat stress markedly reduced milk production and milk components while increasing markers of leaky gut and inflammation. In contrast, vitamin D3 and Ca supplementation reduced hyperthermia (d 7-14), markers of leaky gut, and inflammation independent of dietary concentrations of vitamin E and Se.

Relationship of Extravascular Lung Water and Pulmonary Vascular Permeability to Respiratory Mechanics in Patients with COVID-19-Induced ARDS

During acute respiratory distress syndrome (ARDS), the increase in pulmonary vascular permeability and lung water induced by pulmonary inflammation may be related to altered lung compliance. A better understanding of the interactions between respiratory mechanics variables and lung water or capillary permeability would allow a more personalized monitoring and adaptation of therapies for patients with ARDS. Therefore, our main objective was to investigate the relationship between extravascular lung water (EVLW) and/or pulmonary vascular permeability index (PVPI) and respiratory mechanic variables in patients with COVID-19-induced ARDS. This is a retrospective observational study from prospectively collected data in a cohort of 107 critically ill patients with COVID-19-induced ARDS from March 2020 to May 2021. We analyzed relationships between variables using repeated measurements correlations. We found no clinically relevant correlations between EVLW and the respiratory mechanics variables (driving pressure (correlation coefficient [CI 95%]: 0.017 [-0.064; 0.098]), plateau pressure (0.123 [0.043; 0.202]), respiratory system compliance (-0.003 [-0.084; 0.079]) or positive end-expiratory pressure (0.203 [0.126; 0.278])). Similarly, there were no relevant correlations between PVPI and these same respiratory mechanics variables (0.051 [-0.131; 0.035], 0.059 [-0.022; 0.140], 0.072 [-0.090; 0.153] and 0.22 [0.141; 0.293], respectively). In a cohort of patients with COVID-19-induced ARDS, EVLW and PVPI values are independent from respiratory system compliance and driving pressure. Optimal monitoring of these patients should combine both respiratory and TPTD variables.

Phenotypic plasticity in desiccation physiology of closely related, range restricted and broadly distributed fruit fly species

Abstract Variation in geographical range size among closely related species may result from differences in physiological traits, such as desiccation tolerance, that enable these species to interact with their environment or adapt to new surroundings. We tested the hypothesis that insect species with a broader geographical range have either a higher basal desiccation tolerance or mount a more plastic response than more narrowly distributed species by exposing four fruit fly species (Ceratitis capitata, Ceratitis rosa, Ceratitis cosyra and Ceratitis podocarpi) to one of three acclimation treatments (control: standard relative humidity (RH) and temperature; desiccation: standard temperature and low humidity; and temperature: low RH and high temperature) and measuring metabolic rate, activity, water loss rates and survival. The targeted physiological responses differed between species and acclimation treatments. Survival of the widely distributed C. capitata improved by up to 43% after short‐term exposure to high temperature and desiccation (35°C; 0% RH) treatment, while survival in the more narrowly distributed species only improved by 4%–30% after a desiccation treatment (25°C; 0% RH). Less water was lost by broadly distributed C. capitata through excretion after both high temperature and desiccation treatments, but only activity and respiratory water loss (RWL) were reduced after the temperature treatment, and total water loss and cuticular water loss declined after the desiccation treatment. The narrowly distributed C. rosa also lost less water through excretion after both acclimation treatments but showed reduced cuticular and RWL only after desiccation. While basal tolerance in C. cosyra was high, acclimation responses in this species and C. podocarpi were insignificant in that they did not produce a measurable survival benefit. Broadly distributed species successfully employed unique combinations of physiological strategies, with some having highly flexible responses to stressful environmental conditions, which ultimately results in beneficial acclimation to enhance survival during dry conditions. By contrast, range restricted species showed limited responses to desiccation stress. Flexible desiccation responses likely contribute to species geographical ranges in changing climate conditions. Read the free Plain Language Summary for this article on the Journal blog.

Sweating Rate and Sweat Chloride Concentration of Elite Male Basketball Players Measured With a Wearable Microfluidic Device Versus the Standard Absorbent Patch Method

The purpose of this study was to compare a wearable microfluidic device and standard absorbent patch in measuring local sweating rate (LSR) and sweat chloride concentration ([Cl-]) in elite basketball players. Participants were 53 male basketball players (25 ± 3years, 92.2 ± 10.4kg) in the National Basketball Association's development league. Players were tested during a moderate-intensity, coach-led practice (98 ± 30min, 21.0 ± 1.2 °C). From the right ventral forearm, sweat was collected using an absorbent patch (3M Tegaderm™ + Pad). Subsequently, LSR and local sweat [Cl-] were determined via gravimetry and ion chromatography. From the left ventral forearm, LSR and local sweat [Cl-] were measured using a wearable microfluidic device and associated smartphone application-based algorithms. Whole-body sweating rate (WBSR) was determined from pre- to postexercise change in body mass corrected for fluid/food intake (ad libitum), urine loss, and estimated respiratory water and metabolic mass loss. The WBSR values predicted by the algorithms in the smartphone application were also recorded. There were no differences between the absorbent patch and microfluidic patch for LSR (1.25 ± 0.91mg·cm-2·min-1 vs. 1.14 ±0.78mg·cm-2·min-1, p = .34) or local sweat [Cl-] (30.6 ± 17.3mmol/L vs. 29.6 ± 19.4mmol/L, p = .55). There was no difference between measured and predicted WBSR (0.97 ± 0.41L/hr vs. 0.89 ± 0.35L/hr, p = .22; 95% limits of agreement = 0.61L/hr). The wearable microfluidic device provides similar LSR, local sweat [Cl-], and WBSR results compared with standard field-based methods in elite male basketball players during moderate-intensity practices.

Insights to the 3D internal morphology and metal oxidation states of single atmospheric aerosol particles by synchrotron-based methodology

The morphology and metal oxidation states of atmospheric aerosols are pertinent to their formation processes and ensuing interactions with surrounding gases, vapors and other environments upon deposition, such as human respiratory tract, soil and water. Although much progress has been made in recent years through single-particle techniques, considerably less is known with respect to the three-dimensional (3D) internal morphology of single atmospheric aerosol particles due to the limited penetration depth of electron microscopy. In this study, for the first time, a novel synchrotron-based transmission X-ray microscopy (TXM) methodology has been developed to visualize the 3D internal chemical mixing state and structure of single particles. The results show that the TXM is more applicable to the imaging of solid particles containing high-density elements, e.g., iron (Fe), aluminum (Al), silicone (Si), carbon (C) and sulfur (S), and/or solid particles of sizes larger than about 100 nm. In addition, the TXM is capable to reveal the fine 3D topographic features of single particles. The derived 3D internal and external information would be difficult to discern in the 2D images from electron microscopy. The TXM 3D images illustrate that aerosol particles exhibit complex internal mixing state and structure, e.g., homogeneously-, heterogeneously-mixed, multiple inclusions, fibrous, porous, and core-shell configuration. When coupled with the synchrotron-based X-ray fluorescence spectrometry (XRF) and absorption near-edge spectroscopy (XANES) of an X-ray nanoprobe in the energy range of 4–15 keV, the 3D morphology of single particles is further supplemented with the spatial distribution and oxidation sates of selected elements, including Fe, vanadium (V), manganese (Mn), chromium (Cr) and arsenic (As). The presented cross-platform, synchrotron-based methodology shows promise in complementing existing single-particle techniques and providing new insights to the heterogeneity of single-particle micro-physicochemical states relevant to the aerosol chemistry, optical properties, and their environmental and health impacts.

HEPA filter improves homemade cloth mask to surgical mask standards

Hydrophobic inner filters can stop respiratory disease-infected water droplets from passing through cloth masks.

Erratum: Myocardial Infarction by Percutaneous Embolization Coil Deployment in a Swine Model.

An erratum was issued for:Myocardial Infarction by Percutaneous Embolization Coil Deployment in a Swine Model. The Protocol and Discussion sections were updated. Step 3.5 was updated from: Clean the right femoral area with surgical soap and antiseptic povidone-iodine solution under sterile conditions to: Clean the right femoral area with surgical soap followed by alternating antiseptic povidone-iodine solution and alcohol 3 times under sterile conditions. Section 9 was updated from: 9. Euthanasia method Under previous sedation and anesthesia, as previously described, administer an IV sodium thiopental overdose (200 mg/kg). Confirm cardiorespiratory arrest and death by monitoring vital signs (electrocardiogram, blood pressure, capnography). to: 9. Postoperative pain assessment and monitoring During the post-surgical follow-up, monitor the general condition of the animals, including the respiratory rate, food and water intake, activity and interaction with the other individuals, appearance and coloration of the skin, and the evolution of the surgical wound. Apply a daily supervision protocol according to the following scoring criteria: - Weight: 0: Normal 1: <10% weight loss 2: 10-20% weight loss 3:> 20% weight loss - Body condition: 0: Good: non-prominent vertebrae, pelvic or spinal bones 2: Regular: evidence of spinal segmentation, palpable pelvic bones 3: Emaciation: extremely marked skeleton, little or no meat to cover - Behavior: 0: Normal: Active and interactive in your environment 1: Slight decline in activity and less interactive 2: Abnormal: pronounced decline in activity, isolated 3: Abnormal: Immobile or hyperactivity, possible self-harm - Physical appearance: 0: Normal: skin/hair shiny and eyes bright 1: Disappears embalming, skin/hair without shine 2: Poor skin/nasal secretions 3: Poor skin, abnormal or hunched posture - Behavioral disorders: 0: None 1: Inability to move normally 2: Unable to reach food/drink, isolated from other animals 3: Intention to hide/corner, does not respond to stimuli (dying) - Clinical signs: 0: None 1: Hypothermia, fever, mild respiratory failure 2: Infection of the surgical wound, moderate respiratory failure with muco-bloody secretions 3: Heart failure, severe respiratory failure (cyanosis, open mouth) Score: - 1-5: Supervise the animals once a day. - 6-12: Provide supportive therapy if necessary. - Any animal with a score of 3 in any of the above parameters or with a total score >12 will be euthanized. NOTE: The animals should be monitored daily by the animal care staff and twice a week by the research and veterinary team. Although no pain and distress are expected from the procedure, if any animal shows signs of pain, give analgesic therapy (tramadol, oral, 2-4 mg/kg, daily). If any animal does not respond to analgesic medication and shows signs of chronic pain (very low probability), euthanize the animal with an anesthetic overdose (sodium thiopental, IV, 200 mg/kg). If the surgical wound shows signs of infection (low probability) despite the antibiotic therapy administered, treat the wound daily and initiate a new antibiotic regimen (cefquinome sulphate, IM, 2 mg/kg, daily). 10. Euthanasia method Under previous sedation and anesthesia, as previously described, administer an IV sodium thiopental overdose (200 mg/kg). Confirm cardiorespiratory arrest and death by monitoring vital signs (electrocardiogram, blood pressure, capnography).

Assessing the freshwater fluxes related to beef cattle production: A comparison of integrated crop-livestock systems and a conventional grazing system

Beef production is one of the largest water consumers of all food production systems, but there are substantial knowledge gaps about the accounting and interpretation of its freshwater consumption. Moreover, hardly any study has assessed the freshwater fluxes related to beef cattle in integrated crop-livestock (ICL) and crop-livestock-forestry (ICLF) systems. We aimed at quantifying the freshwater fluxes related to beef cattle raised on continuous permanent Brachiaria pastures (CON) or in ICL and ICLF systems in the Brazilian Cerrado in the rainy and dry seasons. Evapotranspiration of forage grass, Eucalyptus trees in ICLF, and from drinking water troughs were calculated from meteorological data collected in the field. Forage accumulation was measured in 11 paddocks over both seasons, and forage intake, drinking water intake, and bodyweight were quantified in 12 growing Nellore heifers per system during two months per season. Freshwater fluxes related to forage production and animals were estimated. Drinking water intake and water intake via forage did not differ (P ≥ 0.073) between the systems, and were greater (P ≤ 0.035) in the rainy than the dry season. Faecal and urinary water excretions were greater in the dry than the rainy season (P ≤ 0.005). The respiratory and cutaneous water losses were greater (P < 0.001) in the rainy than the dry season. In the rainy season, evapotranspiration related to forage accumulation and freshwater consumption for raising beef cattle were greatest in CON, whereas they were greatest in ICLF in the dry season. Although ICLF appeared to be less resilient to dry periods, both integrated systems offer the potential for reduced freshwater consumption for raising beef cattle under grazing conditions, by improving the efficiency of forage use and/or decreasing evapotranspiration of forage.

Spiracular fluttering decouples oxygen uptake and water loss: a stochastic PDE model of respiratory water loss in insects.

In insect respiration, oxygen from the air diffuses through a branching system of air-filled tubes to the cells of the body and carbon dioxide produced in cellular respiration diffuses out. The tracheal system has a very large surface area, so water loss is a potential threat and the question of how insects regulate oxygen uptake and water loss has been an important issue in insect physiology for the past century. The tracheal system starts at spiracles on the surface of the body that insects can open and close, and three phases are observed experimentally, open or closed for relatively long periods of time and opening and closing rapidly, which is called fluttering. In previous work we have shown that during this flutter phase, no matter how small the percentage of time that the spiracles are open, the insect can absorb almost as much oxygen as if the spiracle were always open, if the insect flutters fast enough. This left open the question of water loss during the flutter phase, which is the question addressed in this paper. We formulate a stochastic diffusion-convection model for the concentration of water vapor in the tracheae. Mathematical analysis of the model yields an explicit formula for water loss as a function of six non-dimensional parameters and we use experimental data from various insects to show that, for parameters in the physiological ranges, water loss during the flutter phase is approximately proportional to the percentage of time open. This means that the insect can solve the oxygen uptake versus water loss problem by choosing to have their spiracles open a small percentage of time during the flutter phase and fluttering rapidly.

Divergent physiological acclimation responses to warming between two co-occurring salamander species and implications for terrestrial survival

Small differences in physiological responses are known to influence demographic rates such as survival. We tested for differences in the physiological acclimation responses of two closely-related salamander species that often co-occur, Ambystoma maculatum and A. opacum. Specifically, we measured changes in critical thermal maxima (CTmax), standard metabolic rates (SMRs), and respiratory surface area water loss (RSAWL) following exposure to three temperature treatments under laboratory conditions. While the magnitude of RSAWL and CTmax acclimation responses to warming did not differ between the study species, SMR was maintained across acclimation temperatures among A. maculatum, but declined among A. opacum acclimated to warmer temperatures. Metabolic compensation may facilitate maintained A. maculatum activity levels during warm periods following the relatively cool spring breeding season. In contrast, metabolic suppression may allow A. opacum to conserve energy when exposed to surface conditions during fall breeding and nest guarding. We simulated how these different SMR responses would likely alter post-metamorphic survival in our study species using previously collected data representing six weeks under relatively warm seminatural conditions. Our simulation indicated that, following warming and under identical study conditions, metabolic compensation may allow juvenile A. maculatum to maintain survival likelihoods, whereas metabolic depression may cause juvenile A. opacum to experience increased survivorship. These findings underscore that comparable physiological responses among ecologically similar, sympatric species cannot be assumed. Further, results of this study suggest that metabolic responses may play an important role in amphibian species persistence as temperatures increase due to habitat modification and climate change.

A perspective on insect water balance.

Insects have a large ratio of surface area to volume because of their small size; thus, they face the potential for desiccation in the terrestrial environment. Nonetheless, they constitute over half of identified species and their success on land can be attributed, in part, to adaptations that limit water loss and allow for effective gains of water from food, fluids or atmospheric water vapour. Reduction of water loss from the gut involves sophisticated mechanisms of ion recycling and water recovery by epithelia of the Malpighian tubules and hindgut. Water loss across the body surface is greatly reduced by the evolution of very thin but highly impermeable lipid-rich layers in the epicuticle. Respiratory water loss can be reduced through effective spiracular control mechanisms and by mechanisms for convective rather than diffusive gas exchange. In addition to extracting water from food sources, some insects are capable of absorption of atmospheric water vapour through processes that have evolved independently in multiple groups.

Structure and permeability of the egg capsule of the placental Australian sharpnose shark, Rhizoprionodon taylori

Shark placentae are derived from modifications to the fetal yolk sac and the maternal uterine mucosa. In almost all placental sharks, embryonic development occurs in an egg capsule that remains intact for the entire pregnancy, separating the fetal tissues from the maternal tissues at the placental interface. Here, we investigate the structure and permeability of the egg capsules that surround developing embryos of the placental Australian sharpnose shark (Rhizoprionodon taylori) during late pregnancy. The egg capsule is an acellular fibrous structure that is 0.42 ± 0.04 μm thick at the placental interface between the yolk sac and uterine tissues, and 0.67 ± 0.08 μm thick in the paraplacental regions. This is the thinnest egg capsule of any placental shark measured so far, which may increase the diffusion rate of respiratory gases, fetal wastes, water and nutrients between maternal and fetal tissues. Molecules smaller than or equal to ~ 1000 Da can diffuse through the egg capsule, but larger proteins (~ 3000–26,000 Da) cannot. Similar permeability characteristics between the egg capsule of R. taylori and other placental sharks suggest that molecular size is an important determinant of the molecules that can be exchanged between the mother and her embryos during pregnancy.

Burrow Morphology of Brachyuran Crab Dotilla blanfordi Alcock, 1900 from Gulf of Khambhat, Gujarat, India

The present study was conducted to understand the burrow morphology of brachyuran crab Dotilla blanfordi Alcock, 1900 at Dandi beach located in Gulf of Khambhat of Gujarat state, India. Burrows were selected randomly and their opening diameter was recorded. Diluted resin was poured in the burrows to generate burrow cast. If the occupant crab emerges out of the burrow, it was captured and carapace width and gender was recorded. The shapes of complete burrow casts were identified and measurements of various morphological characters of burrow cast were recorded. Total 7 different burrow shapes were identified, out of which single tube burrow was the most common as compared to other burrow shapes. The crab carapace width showed significant relationship with burrow opening diameter, burrow depth, burrow length and burrow volume. Juveniles (3.45 mm CW) were making burrow of all the seven shapes. Burrow depth, length and volume were significantly higher in adult crabs as compared to juveniles. No significant variation was observed between burrows of male and female individuals. The present study showed that burrow morphology is highly affected by the crab body size and also varies significantly with different life stages of the crab. Juveniles make shallow and simple burrows as their smaller gill areas stores lesser amount of respiratory water which needs to be changed frequently. However, adults make complex burrows to perform various tasks including copulation and reproduction.