Why Do Birds False Alarm Flight?

False alarm flighting in avian flocks is common, and has been explained as a maladaptive information cascade. If false alarm flighting is maladaptive per se, then its frequency can only be explained by it being net adaptive in relation to some other benefit or equilibrium. However, I argue that natural selection cannot distinguish between false and true alarm flights that have similar energetic costs, opportunity costs, and outcomes. False alarm flighting cannot be maladaptive if natural selection cannot perceive the difference between true and false alarm flighting. Rather, the question to answer is what false and true alarm flighting both have in common that is adaptive per se. The fire drill hypothesis of alarm flighting posits that false alarm flights are an adaptive investment in practicing escape. The fire drill hypothesis predicts that all individuals can benefit from practicing escape, particularly juveniles. Flighting practice could improve recognition of and response time to alarm flighting signals, could compensate for inter-individual and within-day weight differences, and could aid the development of adaptive escape tactics. Mixed-age flocks with many juveniles are expected to false alarm flight more than adult flocks. Flocks that inhabit complex terrain should gain less from escape practice and should false alarm flight less. Behavioural ecology framings can be fruitfully complemented by other research traditions of learning and behaviour that are more focused on maturation and motor learning processes.

Using commercial enzyme immunoassay for measuring pregnancy-associated glycoproteins to diagnose pregnancy in dairy cows under field conditions in Algeria

The purpose of the present work was to study effectiveness for early pregnancy diagnosis in cattle of the new enzyme immunoassay (EIA) sandwich kit commercially available based on the measurement of pregnancy-associated glycoproteins (PAGs). 120 Holstein-Friesian cattle of mixed age and parity were comprised from different dairy herds. The pregnant females (n = 68) were diagnosed by ultrasonography at day 35-40 after artificial insemination and confirmed by transrectal exploration at 2-3 months after AI. The non-pregnant females (n = 52) were housed in the absence of males during the experimental period. Blood samples were collected from coccygeal vessels of females into EDTA tubes. The serum was obtained by centrifugation and the serum was stored at - 20 C until assay. The PAG concentrations in pregnant and non-pregnant females were determined in serum by EIA kit. The reproducibility inter- and intra-assay of the PAG-EIA is satisfactory (2.78 and 13.19 %, respectively). The accuracy ( 94.8 %) and the test of parallelism were largely acceptable. No cross-reaction was observed with the different hormones tested at different dilutions. PAG-EIA system gave 100 % sensitivity and negative predictive values. Whereas, specificity and positive predictive value were 91.93 and 71.15 %, respectively. The accuracy of pregnancy diagnosis by PAG-EIA was 87.5 %. In conclusion, the present study shows clearly that the EIA kit can be used to measure PAG in serum cows for the detection of gestation in Algeria. Therefore, this alternative technique could be recommended to replace the radioactive methods in immunoassays to improve the reproductive performances and an efficient tool for reproductive management of dairy cattle.

The Influence of Age and Winter Environment on Protein Block Intake Behavior of Beef Cattle Winter Grazing Mixed-Grass Rangelands

This study evaluated the influence of cow age and temperature adjusted for windchill (Twindchill) on supplement intake behavior of cattle winter grazing rangelands. A mixed-age herd of Angus-based cows (291 and 316 in year 1 and 2, respectively) were classified by age (1-, 2-, 3-, 4-, 5–7-, and ≥8-year-old) and grazed rangeland pasture (329-ha) for two consecutive winters. Cows were provided free-choice access to supplement protein blocks in a SmartFeedPro self-feeder system. An Onset HOBO Weather Station collected data throughout the grazing period. Supplement intake (expressed as kg∙d−1 and g∙kg body weight−1), the coefficient of variation in supplement intake and intake rate (g∙min−1) displayed Twindchill × cow age × year interactions (p ≤ 0.02). In general, cow age displayed a quadratic effect on all supplement intake variables (p ≤ 0.04), where 3- to 4-year-old cattle had the greatest supplement intake with the least variation, while yearling cattle had the least amount of supplement intake and the greatest variation. In conclusion, winter environmental conditions interacted with cow age to affect cattle supplement intake behavior and, consequently, the efficacy of nutrient delivery systems for beef cattle winter grazing on rangelands.

Systematic Review of Psychological Aging Research in Nepal

Nepal faces unprecedented levels of aging similar to trends in many less well-resourced countries. It has limited capacity to address the medical, social and psychological needs of older persons. Difficult choices regarding allocation of resources will be needed. In this review, we hope to clarify what is already known in aging research in Nepal. The databases APA PsychINFO and PubMed were searched. The inclusion criteria were peer-reviewed articles on i) psychological constructs and mental illnesses, ii) use of original data, iii) inclusion of senior participants and iv) studies conducted in Nepal. Studies that included mixed age group and cross-country comparisons were excluded from this review. The initial search resulted in 76 articles from APA PsychINFO and 590 articles from PubMed. Articles were reviewed independently for inclusion and exclusion criteria. A total of 49 articles were included in the final list. Preliminary results showed that the largest share of articles focused on depression (32.1%), followed by quality of life/life satisfaction or loneliness(18.9%). A large number of studies also examined prevalence rates of psychiatric and neurocognitive disorders (22.6%). Common conditions, like dementia and delirium were studied only in 1.9% and 3.8% of published studies respectively. All of the studies were cohort-based and none focused on evaluations of psychosocial/medical interventions. Robust intervention studies are needed to help improve the lives of seniors in Nepal. To our knowledge this is the first comprehensive review of published articles on psychological construct in aging populations in Nepal.

Age and Body Condition Influence the Post-Prandial Interleukin-1β Response to a High-Starch Meal in Horses

Older horses and those prone to obesity may be at a higher risk for inflammation than younger and leaner counterparts. Previous research indicated a postprandial elevation in plasma concentrations of interleukin-1β (IL-1β), a pro-inflammatory cytokine, after consuming 1.2 g of non-structural carbohydrates/kilogram of body weight. However, these studies utilized horses of mixed age and body condition. The current study evaluated post-prandial IL-1β concentrations in horses specifically comparing lean to over-conditioned and middle aged to older. Our results suggest that at least two weeks of daily consumption of a high non-structural carbohydrate diet is required to induce a post-prandial increase in IL-1β concentrations in younger and leaner horses. In opposition to this, older and over-conditioned horses experience plasma increased on the first day of feeding and thereafter. Feeding management practices of older and over-conditioned individuals should emphasize lower non-structural carbohydrate intakes and further research should elucidate mechanisms of IL-1β activation.

Younger and Older Together: Children's Interactions in a Mixed-Age Early Childhood Centre

<p>Since industrialisation, children have increasingly become educated in age-bands to facilitate manageability. The contemporary 21st century Western world further limits mixed-age interaction for young children, yet there is little concern expressed about educational segregation based on age. At the same time, mixed-age settings have been noted to be beneficial for children's learning. This qualitative exploratory study, situated within a socio-cultural framework, considered the nature of children's interactions in one mixed-age Playcentre. Using narrative records that captured the nuances of the social interactions of three focus children, over the course of three Playcentre sessions for each child, the experiences of an 18-month aged girl, a 3-year-3-month old boy and a 4-year-7-month old girl were analysed to explore the qualitative nature of the social interactions that are enabled in a mixed-age early childhood setting. This study supports earlier studies that indicate that age makes a difference to the type of interactions that children engage in. In this study age impacted on the social interaction techniques and strategies that the focus children applied and was also a factor when choosing a peer to engage with. Older children were the ideal child to observe, and to engage with, and this assigned an unspoken leadership role to these older children. Yet, all children were active in their life-world with all being able to contribute to the interactions at the Playcentre, regardless of age. Each of the focus children took responsibility for one another, contributing to the upholding of centre rules and regulations while also respecting each others' needs. I argue that the children's social interactions within this Playcentre created a sense of togetherness within a community; this was the central feature of children's social experiences in this mixed-age setting.</p>

Younger and Older Together: Children's Interactions in a Mixed-Age Early Childhood Centre

<p>Since industrialisation, children have increasingly become educated in age-bands to facilitate manageability. The contemporary 21st century Western world further limits mixed-age interaction for young children, yet there is little concern expressed about educational segregation based on age. At the same time, mixed-age settings have been noted to be beneficial for children's learning. This qualitative exploratory study, situated within a socio-cultural framework, considered the nature of children's interactions in one mixed-age Playcentre. Using narrative records that captured the nuances of the social interactions of three focus children, over the course of three Playcentre sessions for each child, the experiences of an 18-month aged girl, a 3-year-3-month old boy and a 4-year-7-month old girl were analysed to explore the qualitative nature of the social interactions that are enabled in a mixed-age early childhood setting. This study supports earlier studies that indicate that age makes a difference to the type of interactions that children engage in. In this study age impacted on the social interaction techniques and strategies that the focus children applied and was also a factor when choosing a peer to engage with. Older children were the ideal child to observe, and to engage with, and this assigned an unspoken leadership role to these older children. Yet, all children were active in their life-world with all being able to contribute to the interactions at the Playcentre, regardless of age. Each of the focus children took responsibility for one another, contributing to the upholding of centre rules and regulations while also respecting each others' needs. I argue that the children's social interactions within this Playcentre created a sense of togetherness within a community; this was the central feature of children's social experiences in this mixed-age setting.</p>

Positive Affirmations and Their Effect on Children’s Moods in an Elementary Classroom

This study set out to find out how positive affirmations affect children in an elementary aged classroom. The study consisted of thirteen students in a mixed age Montessori classroom. The study lasted ten days and for six of those days the students simply rated their mood. For the next six days students said positive affirmations in the morning and rated themselves like they did the previous six days. This study used the Mood Meter as the scale for students’ moods. The Mood Meter was created by the Yale Center for Emotional Intelligence. This study used Evaluation Research Method IV in order to see that by implementing positive affirmations into a classroom would children’s moods increase. The study did not find a correlation between students saying positive affirmations and students’ moods. Although this study did not find a correlation between positive affirmations and students’ moods, the method that was used can be replicated on a larger population and longer study in order to see the true effects.

PSXI-27 Comparison of live weight, backfat depth, and loin eye muscle measurements in ewe and ram lambs

Application of ultrasound carcass trait scanning in meat animals enhances the selection efficiency and accuracy. One hundred and sixty-two mixed age Katahdin ewes were selected based on ultrasound carcass traits and bred in a high lean muscle selection (n=81) and control (n=81) flocks, respectively in December 2019. Carcass traits including loin eye area (LEA), loin eye muscle width (LEW) and depth (LED), and back-fat depth (BFD) were measured for sires, dams, and their progeny lambs. Birth weight (BW), rearing rank, sex, and weaning weight (WW=90 d) and post weaning weight (PW=120 d) were recorded for progeny. Post-weaning live weight, LEA and BFD values were calculated for deriving an expected progeny difference lists and ewe replacements. Retaining ram lambs (25% male progeny) were recorded for live weight, carcass trait scanning, and breeding values estimate at six-month old as breeding sires. There was no difference between selection and control progeny for WW, PW, BFD and LEA measurements. Means for BW, WW, PW, LEA, LEW, LED, and FBD in progeny were 3.77 ±0.56, 22.13 ±2.98, 24.48 ±3.08 kg, 5.9 ±0.1cm², 4.4 ±0.5 cm, 1.9 ±0.2 cm and 2.9 ±2.6 mm. However, the WW, PW, LEA, and LEW were measured significantly (P &lt; 0.05) greater for ram lambs (20.6 kg, 25.5 kg, 6.1 cm², 4.5 cm) over ewe lambs (19.5 kg, 23.8 kg, 5.7 cm², 4.3 cm). Single born lambs were significantly (P &lt; 0.01) heavier at birth, weaning and post-weaning, and measured greater value for LEA and LED than twin birth or reared lambs. The statistical analysis showed WW was significantly (P &lt; 0.01) correlated with PW (r=0.71) and both WW and PW correlated with LEA (r=0.5) but not with BFD. The result indicates that lean animal selection using ultrasound carcass trait scanning will improve early age selection efficiency and accuracy.

Modeling the growth and sporulation dynamics of the macroalga Ulva in mixed-age populations in cultivation and the formation of green tides

Ulva is a widespread green algal genus with important ecological roles and promising potential as a seagriculture crop. One of the major challenges when cultivating Ulva is sudden biomass disappearance, likely caused by uncontrolled and unpredicted massive sporulation. However, the dynamics of this process are still poorly understood. In this study, we propose a mathematical model describing the biomass accumulation and degradation of Ulva, considering the potential impact of sporulation inhibitors. We developed a differential equation model describing the time evolution of Ulva biomass. Our model simulates biomass in compartments of different Ulva ‘age’ classes, with varying growth and sporulation rates. Coupled with these classes is a differential equation describing the presence of a sporulation inhibitor, produced and secreted by the algae. Our model mimics observed Ulva dynamics. We present Ulva's biomass accumulation under different initial algae population age distributions and sporulation rates. Furthermore, we simulate water replacement, effectively depleting the sporulation inhibitor, and examine its effects on Ulva's biomass accumulation. The model developed in this work is the first step towards understanding the dynamics of Ulva growth and degradation. Future work refining and expanding our results should prove beneficial to the ecological research and industrial growth of Ulva.