Comparative analysis of thermal indices for modeling cold and heat stress in US dairy systems.

Quantifying the impact of thermal stress on milk yields is essential to effectively manage present and future risks in dairy systems. Despite the existence of numerous heat indices designed to communicate stress thresholds, little information is available regarding the accuracy of different indices in estimating milk yield losses from both cold and heat stress at large spatio-temporal scales. To address this gap, we comparatively analyzed the performance of existing thermal indices in capturing US milk yield response to both cold and heat stress at the national scale. We selected four commonly used thermal indices: the Temperature and Humidity Index (THI), Black Globe Humidity Index (BGHI), Adjusted Temperature and Humidity Index (THIadj), and Comprehensive Climate Index (CCI). Using a statistical panel regression model with observational and reanalysis weather data from 1981-2020, we systematically compared the patterns of yield sensitivities and statistical performance of the four indices. We found that the US state-level milk yield variability was better explained by the THIadj and CCI, which combine the effects of temperature, humidity, wind, and solar radiation. Our analysis also reveals a continuous and nonlinear responses of milk yields to a range of cold to heat stress across all four indices. This implies that solely relying on fixed thresholds of these indices to model milk yield changes may be insufficient to capture cumulative thermal stress. Cold extremes reduced milk yields comparably to those impacted by heat extremes on the national scale. Additionally, we found large spatial variability in milk yield sensitivities, implying further limitations to the use of fixed thresholds across locations. Moreover, we found decreased yield sensitivity to thermal stress in the most recent two decades, suggesting adaptive changes in management to reduce weather-related risks.

A meta-analysis of the relationship between milk protein production and absorbed amino acids and digested energy in dairy cattle.

Milk protein production is the largest draw on AA supplies for lactating dairy cattle. Prior NRC predictions of milk protein production have been absorbed protein (MP)-based and utilized a first-limiting nutrient concept to integrate the effects of energy and protein, which yielded poor accuracy and precision (root mean squared error (RMSE) > 21%). Using a meta-data set gathered, various alternative equation forms considering MP, absorbed total essential AA (EAA), absorbed individual EAA, and digested energy (DE) supplies as additive drivers of production were evaluated, and all were found to be superior in statistical performance to the first limitation approach (RMSE = 14-15%). Inclusion of DE intake and a quadratic term for MP or absorbed EAA supplies were found to be necessary to achieve intercept estimates (non-productive protein use) that were similar to the factorial estimates of NASEM. The partial linear slope for MP was found to be 0.409, which is consistent with the observed slope bias of -0.34g/g when a slope of 0.67 was used for MP efficiency in a first-limiting nutrient system. Replacement of MP with the supplies of individual absorbed EAA expressed in g/d and a common quadratic across the EAA resulted in unbiased predictions with improved statistical performance as compared with MP-based models. Based on Akaike's Information Criterion (AIC) and biological consistency, the best equations included absorbed His, Ile, Lys, Met, Thr, the non-essential AA, and individual DE intakes from fatty acids, neutral detergent fiber, residual organic matter, and starch. Several also contained a term for absorbed Leu. These equations generally had RMSE of 14.3% and a concordance correlations (CCC) of 0.76. Based on the common quadratic and individual linear terms, milk protein response plateaus were predicted at approximately 320 g/d of absorbed His, Ile, and Lys; 395 g/d of absorbed Thr; 550 g/d of absorbed Met; and 70 g/d of absorbed Leu. Therefore, responses to each except Leu are almost linear throughout the normal in vivo range. De-aggregation of the quadratic term and parsing to individual absorbed EAA resulted in non-biological estimates for several EAA indicating over-parameterization. Expression of the EAA as g/100 g of total absorbed EAA or as ratios of DE intake and using linear and quadratic terms for each EAA resulted in similar statistical performance, but the solutions had identifiability problems and several non-biological parameter estimates. The use of ratios also introduced nonlinearity in the independent variables which violates linear regression assumptions. Further screening of the global model using absorbed EAA expressed as g/d with a common quadratic using an all-models approach, and exhaustive cross-evaluation indicated the parameter estimates for body weight, all 4 DE terms, His, Ile, Lys, Met, and the common quadratic term were stable, while estimates for Leu and Thr were known with less certainty. Use of independent and additive terms and a quadratic expression in the equation results in variable efficiencies of conversion. The additivity also provides partial substitution among the nutrients. Both of these prevent establishment of fixed nutrient requirements in support of milk protein production.

Early Childhood Caries and Dental Care Utilization in Mangalore, India: Parents' Perceptions.

BACKGROUND: Parents often underuse dental care services for their children with early childhood caries (ECC), resulting in a high burden of untreated dental caries. AIM: To describe parental perceptions and challenges in dental care utilization for their children with ECC. DESIGN: A descriptive qualitative study was conducted with parents of children with ECC seeking dental care in Mangalore, India. Data were collected through focus group discussions using an interview guide. Manual line-by-line coding and content analysis methods were used for data analysis. RESULTS: Three categories were generated from data obtained through 5 focus groups of 27 participants: dental care visiting patterns, the significance of dental visits, and challenges to dental care utilization. Parents would only visit the dentist when they perceived their children's tooth problems. The challenges faced include time constraints, misinformation, lack of awareness and motivation, costs, fear, and anxiety of the children and the parents themselves. Parents perceived improvements in the awareness of their children's oral health and quality of life after dental visits. CONCLUSION: Attending dental services to treat their children's tooth problems was the primary way of attaining awareness about prevention among the parents of children with ECC. Increased oral health awareness and improved quality of life can motivate parents to seek further dental care for their children. Collaboration with multidisciplinary stakeholders is required to improve oral health awareness among parents of children with ECC. KNOWLEDGE TRANSFER STATEMENT: The study's results will help plan targeted preventive programs for children with ECC. The study suggests dental care utilization by children with ECC is based on parental perceptions of their children's tooth problems. It outlines the challenges that affect dental visits of children with ECC and the role of multidisciplinary stakeholders. Improved oral health awareness and quality of life following dental treatment can facilitate further dental visits.

Comparative analysis of diagnostic methods and risk factors for Aelurostrongylus abstrusus infection in brazilian cats.

This study aimed to prospectively evaluate the risk factors of infection by Aelurostrongylus abstrusus in Brazilian cats with cough and/or radiographic changes, using as diagnostic tools the Baermann method (BM), polymerase chain reaction (PCR) of feces, bronchoalveolar lavage fluid (BALF), and cytology. Forty-three cats that were presented with cough or lung radiographic abnormalities compatible with bronchoalveolar disease were included in the study. After clinical evaluation, feces samples were collected to investigate lungworm parasitism through BM and PCR. BALF was performed to provide samples for cytology, bacteriology, and fungal culture. Stool PCR was considered the gold standard for diagnosis tests, and the other methods were evaluated by their agreement. PCR presented 74% (32/43) of positivity for A. abstrusus, while in the BM, 41% (18/43) were positive. BM showed sensitivity of 56.25% and specificity of 100% when compared with PCR. No larva was found in the cytological evaluation of 21 BALF samples. Lungworm is an important cause of bronchopulmonary disease in domestic cats in Brazil and should be included as a differential diagnosis when a cat is presented with cough or radiographic abnormalities. BM is a sensitive, non-invasive, and cheap technique to diagnose the disease, but it is not as sensitive as PCR.

A comparison of different approaches for the analysis of 36Cl in graphite samples.

This study compares different approaches for the quantification of the massic activity of 36Cl in graphite samples. All approaches consisted of a combustion step in combination with a trapping solution to collect the volatile elements. Two different resins were used to separate 36Cl from the matrix (CL resin and PS resin). Liquid scintillation counting (LSC), scintillation counting (SC) and tandem inductively coupled plasma mass spectrometry (ICP-MS/MS) were used to quantify 36Cl activity. The chemical yield in all approaches was determined by means of ion chromatography (IC). In addition, the methods were applied to a real activated graphite sample.

Modeling the relationship between heat stress, feed intake, and day relative to calving in nonlactating dairy cows.

Heat stress (HS) during the dry period can affect animal welfare, health, dry matter intake (DMI), and milk production in the subsequent lactation, which will negatively affect the profitability of dairy farms. In this study, the objective was to model the changes in DMI in pregnant nonlactating heat-stressed dairy cows with or without access to evaporative cooling systems. A database was built, composed of individual DMI records from 244 pregnant nonlactating dairy cows from an average -29.3 d (range: -42 to -21 d; SD: ±7.54 d) to -1 d relative to calving (DRC) and housed in environmental conditions in which temperature-humidity index (THI) ranged from 58.4 to 83.3, with or without access to evaporative cooling systems. Generalized additive mixed-effects models were used to describe the relationships of DMI with HS and DRC. Changes in DMI with the increase in THI and the progression of pregnancy in cows with or without evaporative cooling systems were estimated using differential equations. On average, cows housed in barns without evaporative cooling systems had a reduction in DMI of 1.30 kg/d and increased rectal temperature in 0.22°C in relation to those housed in barns with evaporative cooling systems. Dry matter intake decreased as THI increased, but the reduction was greater for noncooled cows as THI values increased. In addition, regardless of the THI, DMI started to decrease at -14 DRC for cooled cows, whereas for noncooled cows it already started at -30 DRC, relative to the previous days evaluated. The intensity of the reduction was lesser for cows that had access to evaporative cooling systems or were in the dry period in May to June as compared with those that were in the dry period in July to August or September to October. The models generated in this study, which include environmental variables, should lead to more accurate predictions of DMI during HS that can be used to formulate diets to meet the needs of the late pregnant cow because it is possible to predict changes in DMI as the heat load and DRC change. Such models are also expected to help dairy nutritionists to decide when and how to apply the dietary strategies available to attenuate the reductions in DMI with the intensity of HS and progression of pregnancy.

Systematic review and meta-analysis of the methionine utilization efficiency in piglets receiving different methionine sources.

Methionine (Met) is an essential amino acid that can be supplied in different chemical forms: DL-Met, L-Met, and OH-Met. This study aimed (i) to model and compare the utilization efficiency of Met for protein deposition (PD) from all sources and (ii) to determine the efficacy and efficiency of these three free Met sources in average daily gain (ADG) of post-weaning pigs fed at or below the Met requirement. A systematic review of the literature resulted in 1 898 papers being screened for title and abstract, with 24 papers meeting the inclusion criteria. The resulting database containing 208 treatment means was used. Prior to model development, the standardized ileal digestible (SID) Met requirements in percentage in the diet were determined using initial and final BW according to the NRC (2012). Data from piglets fed above the SID Met requirements were excluded from the database prior to statistical analysis. Linear mixed-effects regression models predicting ADG as a function of free Met source and SID methionine intake (Meti) or methionine + cysteine intake (Met + cysi) were used to evaluate the efficacy and efficiency of free Met source for weight gain. Moreover, Met retention was modeled assuming that 16% of ADG is deposited as PD, and that Met accounts for 2% of PD. Met utilization efficiency was calculated as Meti after maintenance divided by Met retained in PD. Met utilization efficiency was 77% for the basal diet, decreased (P < 0.01) as Meti increased, and was equal among the three free Met sources. The mixed-effects models showed no difference in ADG for three free Met sources evaluated (P > 0.05). However, the efficacy (ADG per unit of SID Meti) of free Met sources for weight gain differed between piglets fed L and DL-Met (P < 0.05), while there was no difference (P > 0.05) between piglets fed DL and OH-Met or OH and L-Met. On average, piglets fed L-Met gained 40.3 g/d more weight per unit of increase in SID Meti than those fed DL-Met (model 4; P = 0.05). The efficacy of free Met sources for ADG was also compared using SID Met + cysi as covariable. Piglets fed L- (+11.7 g/d; P = 0.02) or OH-Met (+11.5 g/d; P = 0.04) gained more weight per gram of SID Met + cysi compared to those fed DL-Met. In conclusion, although the efficacy of DL- and L-Met for ADG differed, the efficiency for PD of L-, DL-, and OH-Met were not different in piglets fed at or below Meti requirement.

xButyagrus nabonnandii (Prosch.) Vorster (Arecaceae): a sterile and rare palm with variable morphology?

×Butyagrus nabonnandii (Prosch.) Vorster is known as mule palm due to sterility, but recently, its pollen has been successfully used in backcrosses. It was first described as an artificial cross between Syagrus romanzoffiana (Cham.) Glassman and Butia odorata (Barb.Rodr.) Noblick in 1890. It has been considered rare in nature, and its morphology has been little studied. Thus, we aimed to verify if ×B. nabonnandii is sterile by studying its morphology and seed germination from different natural populations. The hybrid was sampled in four municipalities and is new to three of these. In one of the visited cities, 20 specimens were counted. The vegetative morphology showed less variation than the reproductive. However, part of the vegetative characters differed from previous descriptions relying solely on cultivated specimens. Contrary to previous reports, our data indicate that ×Butyagrus nabonnandii is neither rare nor infertile. Seed germination rates of ×B. nabonnandii are low due to seed predation by beetle larvae and seedless fruit production, which is also observed in the genera of the parental species. Furthermore, as in its parents, the morphology of the hybrid is complex, and future anatomical and molecular approaches are important for a better delimitation and understanding of the biology of ×B. nabonnandii.

Modeling the effects of heat stress in animal performance and enteric methane emissions in lactating dairy cows.

Heat stress (HS) negatively affects dry matter intake (DMI), milk yield (MY), feed efficiency (FE), and free water intake (FWI) in dairy cows, with detrimental consequences to animal welfare, health, and profitability of dairy farms. Absolute enteric methane (CH4) emission, yield (CH4/DMI), and intensity (CH4/MY) may also be affected. Therefore, the goal of this study was to model the changes in dairy cow productivity, water intake, and absolute CH4 emissions, yield, and intensity with the progression (days of exposure) of a cyclical HS period in lactating dairy cows. Heat stress was induced by increasing the average temperature by 15°C (from 19°C in the thermoneutral period to 34°C) while keeping relative humidity constant at 20% (temperature-humidity index peaks of approximately 83) in climate-controlled chambers for up to 20 d. A database composed of individual records (n = 1,675) of DMI and MY from 82 heat-stressed lactating dairy cows housed in environmental chambers from 6 studies was used. Free water intake was also estimated based on DMI, dry matter, crude protein, sodium, and potassium content of the diets, and ambient temperature. Absolute CH4 emissions was estimated based on DMI, fatty acids, and dietary digestible neutral detergent fiber content of the diets. Generalized additive mixed-effects models were used to describe the relationships of DMI, MY, FE, and absolute CH4 emissions, yield, and intensity with HS. Dry matter intake and absolute CH4 emissions and yield reduced with the progression of HS up to 9 d, when it started to increase again up to 20 d. Milk yield and FE reduced with the progression of HS up to 20 d. Free water intake (kg/d) decreased during the exposure to HS mainly because of a reduction in DMI; however, when expressed in kg/kg of DMI it increased modestly. Methane intensity also reduced initially up to d 5 during HS exposure but then started to increase again following the DMI and MY pattern up to d 20. However, the reductions in CH4 emissions (absolute, yield, and intensity) occurred at the expense of decreases in DMI, MY, and FE, which are not desirable. This study provides quantitative predictions of the changes in animal performance (DMI, MY, FE, FWI) and CH4 emissions (absolute, yield, and intensity) with the progression of HS in lactating dairy cows. The models developed in this study could be used as a tool to help dairy nutritionists to decide when and how to adopt strategies to mitigate the negative effects of HS on animal health and performance and related environmental costs. Thus, more precise and accurate on-farm management decisions could be taken with the use of these models. However, application of the developed models outside of the ranges of temperature-humidity index and period of HS exposure included in this study is not recommended. Also, validation of predictive capacity of the models to predict CH4 emissions and FWI using data from in vivo studies where these variables are measured in heat-stressed lactating dairy cows is required before these models can be used.

Relaxation of thoracic aorta and pulmonary artery rings of marmosets (Callithrix spp.) by endothelium-derived 6-nitrodopamine.

6-Nitrodopamine is a novel catecholamine released by vascular tissues, heart, and vas deferens. The aim of this study was to investigate whether 6-nitrodopamine is released from the thoracic aorta and pulmonary artery rings of marmosets (Callithrix spp.) and to evaluate the relaxing and anti-contractile actions of this catecholamine. Release of 6-nitrodopamine, dopamine, noradrenaline, and adrenaline was assessed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The relaxations induced by 6-nitrodopamine and by the selective dopamine D2 receptor antagonist L-741,626 were evaluated on U-46619 (3 nM)-pre-contracted vessels. The effects of 6-nitrodopamine and L-741,626 on the contractions induced by electric-field stimulation (EFS), dopamine, noradrenaline, and adrenaline were also investigated. Both aorta and pulmonary artery rings exhibited endothelium-dependent release of 6-nitrodopamine, which was significantly reduced by the NO synthesis inhibitor L-NAME. Addition of 6-nitrodopamine or L-741,626 caused concentration-dependent relaxations of both vascular tissues, which were almost abolished by endothelium removal, whereas L-NAME and the soluble guanylate cyclase inhibitor ODQ had no effect on 6-nitrodopamine-induced relaxations. Additionally, pre-incubation with 6-nitrodopamine antagonized the dopamine-induced contractions, without affecting the noradrenaline- and adrenaline-induced contractions. Pre-incubation with L-741,626 antagonized the contractions induced by all catecholamines. The EFS-induced contractions were significantly increased by L-NAME, but unaffected by ODQ. Immunohistochemical assays showed no immunostaining of the neural tissue markers S-100 and calretinin in either vascular tissue. The results indicated that 6-nitrodopamine is the major catecholamine released by marmoset vascular tissues, and it acts as a potent and selective antagonist of dopamine D2-like receptors. 6-nitrodopamine release may be the major mechanism by which NO causes vasodilatation.

Ruminal tissue uptake of amino acids in Holstein cows when supply of nutrients within the rumen differs.

Characterisation of amino acid (AA) use by the ruminal vein-drained viscera (RDV) has not been assessed in vivo in dairy cattle, and thus, the extent of ruminal AA use from arterial and postabsorptive blood supplies is unclear. Understanding the complete use of AA by the splanchnic bed may lead to alternative feeding programmes that maximise animal N efficiency. The objective of this work was to determine how different nutritional manipulations affect RDV net appearance and apparent affinity for arterial AA in lactating dairy cattle. Data from two arterio-venous (A-V) difference studies, that used a common set of multicatheterised lactating Holstein cows, assigned to different nutritional treatments, were used to assess ruminal metabolism. Study 1 consisted of three dietary treatments at calving [an alfalfa-glucogenic diet, a glucogenic diet (GLCG), or a ketogenic diet (KETO)] to investigate the effects of dietary nutrients and increasing intake postpartum on RDV metabolism of AA at -14, +4, +15, and +29 days relative to calving (DRTC). Study 2 consisted of two dietary levels of CP (17 or 13%) and three ruminal buffers (ammonia, butyrate, and control) to investigate the level of dietary CP and ruminal fermentation products on RDV metabolism of AA. Blood was collected at 9, 20, and 30 min after buffer administration. Regardless of dietary nutrients or fermentation products present in ruminal fluid, net RDV uptake was positive for most AA, excepting Asp, Cys, Glu, and Ser, which were consistently negative. The general positive net uptakes indicate that any AA potentially absorbed from the rumen were not adequate to meet apparent needs. Ruminal plasma flow and net RDV uptake of Trp, Ala, Gly, and Pro increased linearly with increased DRTC. Feeding KETO or GLCG diets increased ruminal plasma flow, and net RDV uptake of Thr and Gly. Feeding high CP diets increased ruminal uptake of Leu, Phe, and Val. The increased AA uptakes were partially driven by increased plasma flow, however, tissue affinity as reflected in clearance rates also increased or tended to for Met, Trp, Ala, Gly, Pro, and Tyr suggesting that changes in RDV uptake were regulated and not due solely to mass action. In conclusion, splanchnic tissue bed responses to dietary and washed rumen conditions were in part driven by changes in RDV nutrient demand and metabolic activity. The adaptive responses alter the fraction of absorbed AA utilised for non-productive purposes and thus the efficiency of conversion of those AA to product.

Far from urban areas: plastic uptake in fish populations of subtropical headwater streams.

This study investigated the occurrence of plastic particles in the digestive tracts of fish from headwater streams in a human-thinly populated region of the subtropical Sinos River basin in southern Brazil. In total, 258 individuals from 17 species were collected using electric fishing. Thirty-eight percent (38%) of the specimens contained plastic particles. All of them were fibers, with a maximum count of 43 per individual. Plastic fibers were the fourth most abundant food category. Results showed that the uptake of these plastic particles was proportional to the number of ingested food items. Fiber counts in the guts correlated with the uptake of Trichoptera, which are invertebrates using plastic particles to construct their protective cases. No significant difference in plastic uptake was detected between benthic and water column fish. No evidence of bioaccumulation of plastic particles was found in the intestines. The distance from urban areas was not related to the number of ingested plastic particles, concluding that plastics are ubiquitous and available to biota, even in remote locations. The most probable source of these particles is residences close to the streams which discharge the sewage of washing machines without any treatment.

Early Feeding and Weaning Practices of Indian Children with Early Childhood Caries: A Qualitative Exploration.

OBJECTIVE: To describe the early feeding, weaning, and oral hygiene practices of children with early childhood caries (ECC), their parents' knowledge and attitudes regarding infant feeding, and the feeding-related challenges faced by the parents. METHODS: This descriptive qualitative study involved parents of children with ECC who sought dental treatment at an academic dental college in India. Data were collected though focus groups conducted with the 27 parents of children with ECC, using a focus group discussion guide. Data were analyzed using the content analysis method. RESULTS: Community norms, such as learning from the older women in the families or neighborhoods, guided the feeding method, duration of feeding, and weaning. Breastfeeding or bottle-feeding at bedtime beyond 12 mo of age and feeding sugary drinks during weaning were standard practices, despite knowing the risk for dental caries. Parents faced multiple challenges regarding weaning and were unaware of the significance of infant oral hygiene practices. CONCLUSION: In children with ECC, infant feeding practices included prolonged breastfeeding or bottle-feeding beyond the required age, feeding at bedtime, and feeding sugary drinks. Although the parents knew that these feeding habits could increase the risk for caries, they lacked the self-efficacy to translate their knowledge into action during weaning. Also, they lacked awareness regarding infant oral hygiene practices. KNOWLEDGE TRANSFER STATEMENT: The study provides information on the feeding habits of infants that can increase the risk for caries, the challenges faced by the parents of these children in altering these risky habits, and their lack of knowledge on infant oral hygiene practices. Policy/decision makers can advocate for pediatricians and pediatric dentists to incorporate anticipatory guidance or motivational interviewing techniques to tailor the preventive program for ECC for Indian children.

Relaxation of thoracic aorta and pulmonary artery rings of marmosets (Callithrix spp.) by endothelium-derived 6-nitrodopamine

6-Nitrodopamine is a novel catecholamine released by vascular tissues, heart, and vas deferens. The aim of this study was to investigate whether 6-nitrodopamine is released from the thoracic aorta and pulmonary artery rings of marmosets (Callithrix spp.) and to evaluate the relaxing and anti-contractile actions of this catecholamine. Release of 6-nitrodopamine, dopamine, noradrenaline, and adrenaline was assessed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The relaxations induced by 6-nitrodopamine and by the selective dopamine D2 receptor antagonist L-741,626 were evaluated on U-46619 (3 nM)-pre-contracted vessels. The effects of 6-nitrodopamine and L-741,626 on the contractions induced by electric-field stimulation (EFS), dopamine, noradrenaline, and adrenaline were also investigated. Both aorta and pulmonary artery rings exhibited endothelium-dependent release of 6-nitrodopamine, which was significantly reduced by the NO synthesis inhibitor L-NAME. Addition of 6-nitrodopamine or L-741,626 caused concentration-dependent relaxations of both vascular tissues, which were almost abolished by endothelium removal, whereas L-NAME and the soluble guanylate cyclase inhibitor ODQ had no effect on 6-nitrodopamine-induced relaxations. Additionally, pre-incubation with 6-nitrodopamine antagonized the dopamine-induced contractions, without affecting the noradrenaline- and adrenaline-induced contractions. Pre-incubation with L-741,626 antagonized the contractions induced by all catecholamines. The EFS-induced contractions were significantly increased by L-NAME, but unaffected by ODQ. Immunohistochemical assays showed no immunostaining of the neural tissue markers S-100 and calretinin in either vascular tissue. The results indicated that 6-nitrodopamine is the major catecholamine released by marmoset vascular tissues, and it acts as a potent and selective antagonist of dopamine D2-like receptors. 6-nitrodopamine release may be the major mechanism by which NO causes vasodilatation.

Post-COVID-19 tomographic abnormalities.

BACKGROUND: The prevalence of persistent respiratory symptoms tends to be low in patients with a longer recovery time after COVID-19. However, some patients may present persistent pulmonary abnormalities.OBJECTIVE: To evaluate the prevalence of tomographic abnormalities 90 days after symptom onset in patients with COVID-19 and compare two chest high-resolution computed tomography (HRCT) analysis techniques.METHODS: A multicentre study of patients hospitalised with COVID-19 having oxygen saturation <93% on room air at hospital admission were evaluated using pulmonary function and HRCT scans 90 days after symptom onset. The images were evaluated by two thoracic radiologists, and were assessed using software that automatically quantified the extent of pulmonary abnormalities.RESULTS: Of the 91 patients included, 81% had at least one pulmonary lobe with abnormalities 90 days after discharge (84% were identified using the automated algorithm). Ground-glass opacities (76%) and parenchymal bands (65%) were the predominant abnormalities. Both chest HRCT technical assessments presented high sensitivity (95.9%) and positive predictive value (92%), with a statistically significant correlation at baseline (R = 0.80) and after 90 days (R = 0.36).CONCLUSION: The prevalence of pulmonary abnormalities on chest HRCT 90 days after symptom onset due to COVID-19 was high; both technical assessments can be used to analyse the images.

Algorithm development for individualized precision feeding of supplemental top dresses to influence feed efficiency of dairy cattle.

Individualized, precision feeding of dairy cattle may contribute to profitable and sustainable dairy production. Feeding strategies targeted at optimizing efficiency of individual cows, rather than groups of animals with similar characteristics, is a logical goal of individualized precision feeding. However, algorithms designed to make feeding recommendations for specific animals are scarce. The objective of this study was to develop and test 2 algorithms designed to improve feed efficiency of individual cows by supplementing total mixed rations (TMR) with varying types and amounts of top-dressed feedstuffs. Twenty-four Holstein dairy cows were assigned to 1 of 3 treatment groups as follows: a control group fed a common TMR ad libitum, a group fed individually according to algorithm 1, and a group fed individually according to algorithm 2. Algorithm 1 used a mixed-model approach with feed efficiency as the response variable and automated measurements of production parameters and top-dress type as dependent variables. Cow was treated as a random effect, and cow by top-dress interactions were included if significant. Algorithm 2 grouped cows based on top-dress response efficiency structure using a principal components and k-means clustering. Both algorithms were trained over a 36-d experimental period immediately before testing, and were updated weekly during the 35-d testing period. Production performance responses for dry matter intake (DMI), milk yield, milk fat percentage and yield, milk protein percentage and yield, and feed efficiency were analyzed using a mixed-effects model with fixed effects for feeding algorithm, top dress, week, and the 2- and 3-way interactions among these variables. Milk protein percentage and feed efficiency were significantly affected by the 3-way interaction of top dress, algorithm, and week, and DMI tended to be affected by this 3-way interaction. Feeding algorithm did not affect milk yield, milk fat yield, or milk protein yield. However, feeding costs were reduced, and hence milk revenue increased on the algorithm-fed cows. The efficacy of feeding algorithms differed by top dress and time, and largely relied on DMI shifts to modulate feed efficiency. The net result, for the cumulative feeding groups, was that cows in the algorithm 1 and 2 groups earned over $0.45 and $0.70 more per head per day in comparison to cows on the TMR control, respectively. This study yielded 2 candidate approaches for efficiency-focused, individualized feeding recommendations. Refinement of algorithm selection, development, and training approaches are needed to maximize production parameters through individualized feeding.

Egg production and life history of Alona guttata Sars, 1862 (Cladocera, Chydoridae): implications for colonization of temporary ponds / Produção de ovos e história de vida de Alona guttata Sars, 1862 (Cladocera, Chydoridae): implicações para a colonização de lagoas temporárias

Cladocerans are a diverse group of species that show rapid responses to changes in environmental conditions. This adaptive capacity has important implications for egg production and life cycle, especially in transitory environments such as temporary waterbodies. The present study investigated the life history and egg production of Alona gutatta Sars, 1862 (Crustacea, Cladocera), an abundant and frequent species from a high-altitude temporary pond (Lagoa Seca, Minas Gerais, Brazil). Newly hatched neonates were monitored in relation to time of maturation, number of eggs produced per female and time of survival. Neonates required a mean of 8 days to mature. A. guttata survived for a mean of 30.9 ± 8.1 days and produced 2 eggs per brood, generating a mean of 10.95 ± 6.41 neonates during the entire life cycle. The rapid development, short time to produce eggs and long life cycle are important adaptations to the adverse environmental conditions of temporary aquatic environments, which can contribute to the rapid colonization of Alona guttata in transitory ecosystems.

Os cladóceros formam um grupo diverso de espécies que apresentam respostas rápidas às mudanças nas condições ambientais. Essa capacidade adaptativa tem implicações importantes para a produção de ovos e para o ciclo de vida, especialmente em ambientes transitórios, como corpos d'água temporários. O presente estudo investigou a história de vida e a produção de ovos da espécie Alona guttata Sars, 1862 (Crustacea, Cladocera) coletada em uma lagoa temporária de altitude (Minas Gerais, Brasil). Organismos recém eclodidos foram observados (em condições de laboratório) em relação ao tempo de maturação, número de ovos produzidos por fêmea e tempo de sobrevivência. Os neonatos levaram em média 8 dias para atingir o primeiro estágio de maturação. As fêmeas produziram 2 ovos por ninhada e geraram uma média de 10,95 ± 6,41 neonatos durante todo o ciclo de vida. A. guttata apresentou uma média de 30,9 ± 8,1 dias de sobrevivência. O rápido desenvolvimento, o pouco tempo para a produção de ovos e o ciclo de vida longo são adaptações importantes às condições ambientais adversas de ambientes aquáticos temporários, que podem contribuir para a rápida colonização de Alona guttata em ecossistemas transitórios.