Offspring sex ratio in sheep,cattle, goats and pigs: influence of season and lunar phase at conception

This study assessed the relationship between season and lunar phase at conception on offspring sex ratio of four livestock species (sheep, cattle, goats and pigs). The sex of 66,830 lambs (1995–2015); 25,546 calves (2011–2015); 5671 kids (2002–2007) and 1916 piglets was recorded. Moon phases were categorized as either new moon, crescent moon, full moon or decrescent moon. Sex ratio, expressed as proportion of males (males/males + females), was tested against the expected value of 1:1. In sheep, offspring sex ratio and lunar phase were not correlated; season had a significant (p = 0.002) effect on offspring sex ratio. The proportion of males born of spring and winter matings was significantly higher than it was among offspring born of summer (p < 0.05) or autumn (p < 0.01) conceptions. Offspring sex ratios in spring (p < 0.05), autumn (p < 0.01) and winter (p < 0.05) differed significantly from the expected. In cattle, moon phase and season did not affect the offspring sex ratio; however, the interaction effect was highly significant (p = 0.001). The overall piglet sex ratio (0.522), and the sex ratios among piglets conceived during a crescent moon and those conceived in summer differed significantly (p < 0.05) from 1:1. Research including additional factors such as hormonal treatments prior to insemination, food availability, weather and maternal and paternal factors might provide the underlying reasons for the effects of season and moon phase on offspring sex ratio in some livestock species.     

Biological rhythm and emotional and behavioral problems among schoolchildren in Southern Brazil

Emotional and behavioral problems have been considered an indicative of mental disorder in children. Mental health problems affect 10–20% of children and adolescents living in low-income and middle-income countries. Evidence suggests that disruptions in the biological rhythm may be a primary cause of emotional and behavioral changes, which affects several psychological functions and moods. Thus, this study aimed at verifying the association between biological rhythm and emotional and behavioral problems in schoolchildren living in Southern Brazil. This is a cross-sectional study with a school-based sample conducted between August 2015 and November 2016. The presence of emotional and behavioral problems in children was verified by the Strengths and Difficulties Questionnaire (SDQ), parents’ version. This is a 25-item assessment questionnaire used to screen mental health problems in children and adolescents (from 4 to 17 years of age) in the last 6 months. The Biological Rhythm Interview of Assessment in Neuropsychiatry-Kids (BRIAN-K) was used to measure the degree of biological rhythm disruption. The BRIAN-K consists of 20 items; from among these, 17 items are added to generate a quantitative measure, with greater scores indicating more biological rhythm disruption. The final score can also be divided into four subscales: sleep, social rhythm, eating pattern and overall activities. A total of 609 children responded to the assessment instruments. With regard to parents or primary caregiver, 596 completed the assessment and 13 (2%) were not located or refused to participate in the study. Thus, 596 dyads were included in the analysis. Children with emotional and behavioral problems presented higher scores in all domains of BRIAN-K: sleep, social, activity, eating pattern and total score (p < 0.001). The following variables remained associated with emotional and behavioral problems after adjusted analysis: BRIAN-K total score (p < 0.001) and all subscales sleep (p < 0.001), social (p < 0.001), activity (p < 0.001) and eating pattern (p < 0.001). Children with emotional and behavioral problems presented higher biological rhythm disruption when compared with children without emotional and behavioral problems. Our study emphasizes the importance of biological rhythm and its influence on emotional and behavioral problems in schoolchildren. Early detection of any biological rhythm disruption may enhance further assessment of any eventual emotional and behavioral problem and even a psychopathology.     

Effects of lactoferrin supplementation on ileal and total tract nutrient digestibility,gastrointestinal microbial populations,and immune characteristics of ileal cannulated,healthy, adult dogs

Abstract

Orally supplemented lactoferrin derived from bovine milk is purported to have beneficial effects on gut health of animals. Bovine lactoferrin (0, 60, or 120 mg/d) was fed to ileal cannulated, adult dogs in a replicated 3 × 3 Latin square design with 14 d periods. Control dogs tended (p = 0.06) to have higher fecal DM concentrations compared with dogs supplemented with 120 mg/d lactoferrin (34.5 vs. 32.9%). Fecal scores ranged from 3.0 – 3.3, suggesting that feces of all dogs was near the desired consistency, with dogs supplemented with 120 mg/d lactoferrin tending (p = 0.08) to have higher fecal scores. Ileal azoreductase activity tended (p < 0.10) to be higher in dogs supplemented with 60 or 120 mg/d lactoferrin (609 vs. 592 nmol/h per g ileal DM, respectively) as compared with unsupplemented dogs (272 nmol/h per g ileal DM). The following bacterial groups were measured: bifidobacteria, Campylobacter spp., Clostridium spp., eubacteria, Escherichia coli, Lactobacillus spp., Staphylococcus spp., and Streptococcus spp. Fecal streptococci concentrations were lower (p < 0.05) for dogs receiving 60 mg/d lactoferrin (8.60 log₁₀ cfu/g fecal DM) as compared with unsupplemented dogs (9.19 log₁₀ cfu/g fecal DM) or dogs receiving 120 mg lactoferrin/d (9.43 log₁₀ cfu/g fecal DM). Dogs supplemented with 120 mg/d lactoferrin tended (p = 0.08) to have higher fecal indole concentrations as compared to unsupplemented dogs (1.80 vs. 1.46 μmol/g fecal DM). Because most bacterial groups measured were unaffected, it appears that lactoferrin did not exhibit prebiotic activity, and based on the data collected, lactoferrin also did not appear to have major effects on indices of health in the dog.     

Comparative physiological responses of stress in sheep selected for resistance or susceptibility to Haemonchus contortus in semi-arid tropical region during different seasons

The present study was conducted to assess the comparative physiological responses of stress in sheep selected for resistance or susceptibility to Haemonchus contortus in the semi-arid region during different seasons. A total of 20 adult Malpura sheep from resistant and susceptibility line were selected for study. The intensity of strongyle infection, blood biochemical and cortisol levels were estimated monthly basis while meteorological data were collected everyday throughout the year. The temperature-humidity index was the highest during dry-hot season. The faecal egg count increased significantly (p < 0.05) during June–August (rainfall season) in susceptible sheep as compared to resistant sheep. The plasma cortisol level increased significantly (p < 0.05) in both the groups during dry hot (March–May) season and it remained higher in the susceptible line till June–August. The total plasma protein reduced significantly during hot-humid with scantly rainfall (September–November) season as compared to other season in susceptible line. It is pertinent to conclude that though sheep remained in stress during dry hot (March–May) season, but effects of stress on the intensity of strongyle infection and blood biochemical were better tolerated by animals of resistant line during hot-humid season compared to susceptible line under semi-arid region.     

Effects of different processing methods of flaxseed on ruminal degradability and in vitro post-ruminal nutrient disappearance

The aim of the study was to determine the effects of different heat-processing methods of flaxseed on the in situ effective dry matter degradability (EDMD) and the in situ effective crude protein degradability (ECPD). The treatments included roasting, steep roasting, rolled roasting, rolled steep roasting, microwave irradiation and extrusion. Three rumen-fistulated sheep were used for in situ incubations. Furthermore, the effects of heat-processing methods on post-ruminal in vitro nutrient disappearance and total tract disappearance were measured by a three-step in vitro technique. The seeds were roasted and extruded at 140°C to 145°C. One lot of roasted seeds was gradually cooled for about 1 h (roasting) and another lot was held in temperature isolated barrels for 45 min (steep roasting). Moreover, roasted and steep roasted flaxseed was rolled in a roller mill. The lowest and highest EDMD was observed for unheated and extruded flaxseed, respectively (p < 0.05). The highest ECPD was observed for extruded flaxseed (p < 0.05). Roasting and microwave irradiation reduced ECPD of flaxseed (p < 0.05). In vitro post-ruminal disappearance of crude nutrients including fibre fractions was highest for rolled-roasted and rolled steep-roasted flaxseed (p < 0.05). The lowest and highest total tract disappearance rates of crude nutrients and fibre fractions were estimated for unheated and extruded flaxseed, respectively (p < 0.05). The post-ruminal disappearance of crude nutrients was also increased by roasting, in which rolling enhanced this effect. In conclusion, all investigated heat treatments had significant effects on in situ and in vitro degradability of nutrients. As well, rolling of roasted flaxseed enhanced the respective effects. Therefore, different methods of heat processing can be used to modify the feed value of flaxseed for specific purposes.     

Effects of low light and high temperature on pediveligers of the fluted giant clam Tridacna squamosa

ABSTRACT

This paper examines the responses of the fluted giant clam Tridacna squamosa pediveligers to elevated temperature and reduced light levels. In a light reduction experiment, a total of 104,000 T. squamosa pediveligers were exposed to four different levels of shading for approximately one month. The most heavily shaded treatment, at 0.4% of ambient light, had significantly lower survival than the other groups, which all received 1% or more of ambient light. In a second experiment, for approximately two weeks 13,000 T. squamosa pediveligers were divided among three treatments: one at ambient temperature averaging 29.5 °C, and two with elevated temperatures averaging 32.2 °C and 34.8 °C. The elevated temperature treatments resulted in near total mortality. The highest temperature survived by any pediveliger was 32.8 °C. Our results indicate a potential synergetic effect, with turbidity causing giant clam pediveligers to settle in shallower water―where they will likely be exposed to higher temperatures.     

Effects of Parturition and Feeding on Thermal Preference of Atlantic Stingray, Dasyatis sabina (Lesueur)

Synopsis Temperature is the most important and least well documented environmental entity affecting reproduction and feeding of elasmobranch fishes, but it is unclear to what extent these fish may exploit behavioral thermoregulation to optimize physiological processes. Laboratory thermal preference determinations are important to understanding behavioral processes because they provide the vital quantitative link between environment, physiology, and adaptive behavior. Temperature preference data were collected on Atlantic stingrays, Dasyatis sabina (Lesueur) to assess the fishs’ ability to behaviorally optimize feeding and reproduction. Groups of male and pregnant female Atlantic stingrays exhibited statistically higher preferred median temperatures (26.2 and 26.1°C, respectively) than non-pregnant females (25.3°C; One-Way ANOVA on ranked data, F _[2,26] = 3.72, p=0.038). Median preferred temperatures in unfed stingrays of both genders ranged from 24.5 to 31.0°C, whereas, fed fish preferred temperatures between 23.5 and 27.5°C. Unfed stingrays preferred a median temperature of 24.5°C; however, after feeding fish preferred significantly warmer water temperatures of 25.7°C (Wilcoxon one-tail, matched-pairs, signed rank analysis; p<0.088). While overall differences were subtle, small preference adjustments can have important physiological consequences. For example, the 1°C increase seen in pregnant females over non-pregnant fish would reduce gestation time by as much as two weeks. Likewise, by moving to cooler water after feeding, stingrays may increase nutrient uptake efficiency by reducing evacuation rates. Our data indicate that movement and distribution of Atlantic stingrays are dictated, in part, by temperature effects on physiology.     

Effects of the supplementation of distillers’ grape residues on ruminal degradability,whole tract digestibility and nitrogen metabolism in sheep

ABSTRACT

Five ruminally and duodenally cannulated Kazakh male lambs (30 ± 2.75 kg) maintained singly in a metabolic cage were used in a 5 × 5 Latin square experiment to investigate the effect of supplementing a ration with five different levels of distillers’ grape residue (DGR) on ruminal degradability, whole tract digestibility and nitrogen (N) metabolism of growing lambs. The rations were isoenergetic and isonitrogenous and contained 0, 3.85, 7.70, 11.55 and 15.41% DGR (DM basis). Each experimental period lasted for 18 d: 10 d for adaptation to the dietary treatment and 8 d for faecal, urinary, ruminal and duodenal digesta sample collections. The outflow rate of ruminal digesta increased (p = 0.032) linearly with the increased level of dietary neutral detergent fibre content, caused by the supplementation of DGR. As a result, the effective degradability of dry matter and crude protein decreased significantly with the treatments. Although the dietary intake of N, duodenal flow of total N, and the endogenous N at the duodenum were not affected by experimental treatments, N fractions in the digesta were altered. Ruminal microbial N decreased (p < 0.01) linearly; in contrast, ruminal un-degradable protein increased linearly (p < 0.01) in response to the increased addition of DGR. Although there was no significant difference in faecal N among treatments, N retention was increased linearly (p = 0.014), owing to the remarkable reduction (p = 0.016) of urinary N excretion with an increasing level of DGR. The results indicate that the DGR has some potential benefits of increasing the supply of bypass protein and of improving the utilisation efficiency of N for sheep. Therefore, the supplementation of DGR in ruminant feeding is recommended at levels not exceeding 10% of the diet.     

Effect of dietary vegetable oils on the fatty acid profile of plasma lipoproteins in dairy cows

The aim of this study was to elucidate the effect of dietary supplementation of soybean oil (SO) and hydrogenated palm oil (HPO) on the transport of fatty acids (FA) within plasma lipoproteins in lactating and non-lactating cows. Three lactating and three non-lactating Holstein cows were used in two different 3 × 3 Latin square experiments that included three periods of 21 d. Dietary treatments for lactating cows consisted of a basal diet (control; no fat supplement) and fat-supplemented diets containing SO (500 g/d per cow) or HPO (500 g/d per cow). For non-lactating cows, dietary treatments consisted of a basal diet (control; no fat supplement) and fat-supplemented diets containing SO (170 g/d per cow) or HPO (170 g/d per cow). Compared with the control and SO diet, HPO addition increased (p < 0.05) the concentration of C16:0, C18:0, C18:2cis-9,12, C18:3cis-9,12,15 and total saturated and polyunsaturated FA in the plasma of lactating cows. In non-lactating cows, the SO addition increased the plasma concentration of C18:1trans-11. In lactating cows, concentrations of C16:0, C18:0 and total saturated FA were increased (p < 0.05) by HPO addition in the high-density lipoprotein (HDL). Total saturated FA were increased (p < 0.05) by HPO in very-low-density lipoprotein (VLDL). In non-lactating cows, the concentration of C18:0 was increased (p < 0.05) by HPO in HDL, whereas C18:1trans-11 was increased (p < 0.05) by SO in the low-density lipoprotein. Overall, it was found that distribution and transport of FA within the bovine plasma lipoproteins may be influenced by chain length and degree of unsaturation of dietary lipids. Also, the distribution of individual FA isomers such as C18:1trans-11 and C18:2cis-9,trans-11 may vary depending on the physiological state of the cow (lactating or non-lactating), and are increased in plasma (lactating cows) and the HDL (non-lactating cows) when cows are fed SO.     

Efficacy of dietary supplemental insoluble fibrous materials in ameliorating adverse effects of coccidial challenge in broiler chickens

ABSTRACT

The current experiment was designed to examine effects of dietary supplemental sunflower hulls (SH) and rice hulls (RH) on growth performance, carcass traits, intestinal morphology, lesion score and oocyst shedding in broiler chickens exposed to coccidial challenge. A total of 540 broiler chickens (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2 × 3) across 1–14, 14–28 and 28-42-d periods. Experimental treatments consisted of broiler chickens without or with coccidial challenge each offered with three different diets: a basal diet or basal diet supplemented with either RH or SH at 40 g/kg diet, respectively. Infection with Eimeria impaired daily weight gain (DWG) and feed conversion ratio (FCR) of broiler chickens during growing period (p < 0.05) while supplementation of SH or RH reduced the adverse effect of coccidiosis so that birds had similar DWG to those fed the basal diet without infection. However, only dietary SH improved the FCR of broilers challenged with coccidiosis. Regardless of coccidial challenge, dietary access to insoluble fibre improved performance of broilers across the growing period (p < 0.05); however, this effect was not observed during the entire rearing period. Relative weights of liver and pancreas were increased in birds subjected to coccidial challenge on d 21 of age (p < 0.05). Moreover, relative weights of the intestinal segments were enhanced (p < 0.05). Furthermore, gizzard weights were higher in birds receiving diets added with fibre (p < 0.05). Infection with coccidiosis decreased villus height and villus height to crypt depth ratio in duodenum of broilers which received the basal diet compared with those fed the same feed without coccidial challenge (p < 0.05). However, supplemental SH could decrease the negative effect of infection on the noted intestinal morphometric attributes. Similarly, a marked reduction was observed for lesion score and faecal oocyst excretion of challenged broilers fed on dietary supplemental fibre (p < 0.05). In conclusion, supplementation of insoluble fibre could ameliorate negative effects of coccidial challenge on DWG of broiler chickens and inclusion of SH in diet of birds exposed to Eimeria infection could be recommended.     

Blood hormone profiles,physiological variables,and behavioral criteria in Corriedale ewes fed different TMR moisture levels during thermal–humidity exposure

In this study, blood hormone profiles, physiological variables, and behavioral criteria in Corriedale ewes fed total mixed ration (TMR) at different moisture levels during thermal–humidity exposure were evaluated. Nine non-pregnant Corriedale ewes (ave. BW = 41 ± 3.5 kg) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a 3 × 3 Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment). Treatments were TMR (CP (crude protein) = 16.1, TDN (total digestible nutrients) = 69.1%) moisture levels at 40, 50, and 60%. No differences were found in blood hormone profiles including cortisol (μg/dL), immunoglobulin G (mg/dL), triiodothyronine (ng/mL), thyroxin (μg/dL), growth hormone (ng/mL), prolactin (ng/mL), insulin (μU/mL), insulin-like growth factor 1 (ng/mL), aldostrone (ng/dL), antidiuretic hormone (pg/mL), and creatinine (mg/dL) among all treatment groups (p > 0.05). Measurements of physiological variables indicated that heart rate (number of beats/min) in the afternoon was higher in 50 and 60% TMR group than in the 40% group (p < 0.05). No differences were observed in respiratory rate (number/min), panting score, and fecal score among the groups (p > 0.05). The behavior criteria including urine excretion frequency (number/d), fecal excretion frequency (number/d), standing frequency (number/d), resting frequency (number/d), standing duration (min/d), and resting duration (min/d) showed no differences among the treatment groups (p > 0.05). Conclusions drawn indicate the minor impacts of TMR moisture levels up to 60% on behavioral criterions of Corriedale ewes during thermal–humidity exposure, but help smooth down the intensified heat stress conditions over physiological variables and endocrine system.     

Influence of two formulation types and moisture levels on the storage stability and insecticidal activity of Beauveria bassiana

The formulation of mycopesticides may require a physical separation of conidia from the substrate and subsequent drying. In the present study, Beauveria bassiana conidia produced by solid-state fermentation were harvested either through a dry or washing protocol. Washed conidia were used to design a water-dispersible granule (WG) formulation, whereas sieved conidia were mixed with an emulsifiable oil to achieve an oil-based formulation (OD). Potential harmful effects caused by the formulation type on the storage stability and insecticidal activity against Hypothenemus hampei were assessed. As expected, the time for initial conidial germination to drop 50% (GT₅₀) in all treatments was deeply influenced by storage temperatures, which varied from over 180 days at 4 °C to less than 90 days at 35°C. In all four tested temperatures, GT₅₀s for unformulated dry conidia were significantly higher than for those formulated as WG, and the latter was similar to conidia formulated as OD in the two highest temperatures. Residual water content in the OD formulation (1,600 vs. 340?ppm) had a negative influence on conidial survival under storage, whereas WG granules immediately dried after the washing protocol showed conidial germination similar to granules exposed to a slower dehydration regime. Mortality of H. hampei adults exposed to different concentrations of B. bassiana formulated as WG was slightly lower (10–15%) than either the OD or the unformulated conidia. In brief, we have demonstrated that formulation type and their moisture level can affect the storage stability and insecticidal activity of B. bassiana conidia toward the coffee berry borer. Of particular importance, we have shown that drying oils prior to formulation could improve the storage of mycopesticides, an approach that may find industrial applications.     

Effects of environmental enrichment on activity and lameness in commercial broiler production

The aim of this pilot study was to investigate the effects of commercially applied environmental enrichments on behavior and lameness in broilers. Two consecutive flocks of broilers were observed at 16 days and 30 days of age to investigate differences between enriched (peat, bales of lucerne hay, and elevated platforms) and control birds with regards to behavioral activities and lameness. More running (p < .001), worm running (p = .006), play fighting (p = .015), dust bathing (p = .009), and ground pecking while standing (p < .001) were observed at 16 days than at 30 days. Across both ages, enriched birds showed more wing flapping (p = .016), wing stretching (p = .002), body shaking (p = .002), ground scratching (p < .001), and ground pecking while standing (p < .001) and lying (p = .003) compared with control birds. Even when no enrichments were close, enriched birds showed more body shaking (p = .008) and ground pecking while standing (p < 0.001) and lying (p = .010) than birds in comparable locations in control pens. There was a tendency for a lower gait score (i.e., reduced lameness) with the enriched treatment (p = .077). In conclusion, enriched birds showed higher levels of several activities compared with control birds, and demonstrated higher levels in areas where no enrichments were present.     

Social rhythm and other chronobiological findings in juvenile myoclonic epilepsy

We evaluated the correlation between chronobiological variables and characteristics of juvenile myoclonic epilepsy. Sample: 17 individuals epileptic outpatients and respective controls. Instruments: The Social Rhythm Metric for social zeitgebers, lux meter, and an ACT10^® thermistor for activity–rest rhythm, light exposure, and peripheral body temperature. Regularity scores showed an inverse correlation with age at disease onset (r = ?0.5; p < 0.05), but not with disease duration or stabilization time. A significant intergroup difference was recorded for mean diurnal peripheral temperature (p < 0.01) and activity amplitude (= 0.06). There was a correlation between activity and temperature means in both groups. These results underscore the relationship between epilepsy and the biological clock on a physiological level. Epilepsy, in turn, is influenced by the circadian rhythm, indicating the potential involvement of the body’s internal clock in the development of the disease or the seizure recurrence pattern.     

Effects of supplementing two levels of magnesium aspartate and transportation stress on pork quality and gene expression of 𝛍-calpain and calpastatin of finishing pigs

The objective of this study was to investigate the effects of supplementing swine finishing diets with two levels of magnesium aspartate (MgAsp) and short-term transportation stress on blood parameters, pork quality and the mRNA abundance of μ-calpain and calpastatin in muscles of finishing pigs. Thirty-six crossbred finishing pigs (mean BW 90 kg) were assigned randomly to 0, 1000, or 2000 mg supplemental Mg from MgAsp per kg of diet for five days before slaughter. Then six pigs from each dietary treatment were subjected either to no transportation stress (NTS) or 2 h of transportation stress (TS). Transportation stress resulted in higher concentrations (p < 0.01) of serum calcium, glucose and cortisol, lower pH (p < 0.01), higher Warner-Bratzler shear force (WBSF) (p < 0.05) and higher calpastatin mRNA abundance (p = 0.05) of longissimus muscle (LM) compared with NTS treatments. Supplementation of MgAsp in TS treatments increased serum Mg concentration (p < 0.05) at 2000 mg of Mg/kg, reduced drip loss (p < 0.05) and improved pork quality colour (p < 0.05) at 2000 mg of Mg/kg, and decreased 1-day and 3-day WBSF (p < 0.05) at 1000 mg of Mg/kg compared with TS treatments fed the control diet. It is concluded that supplementation of MgAsp improves water-holding capacity and pork colour, and alleviates the negative effects of transportation stress on meat tenderness.     

Residual effects of four pesticides on the predatory bug,Orius albidipennis Reut. (Hem.: Anthocoridae)

Residual effects of abamectin (0.02%), propargite (0.1%), dichlorvos (DDVP) (0.15%) and pymetrozine (0.15%) were determined on Orius albidipennis at laboratory conditions. Planted cucumbers were sprayed with the highest recommended concentrations of all insecticides and experimental treatments were monitored during 20 days based on the period of pesticides residues. On the first day after spraying, the greatest of mortality belonged to dichlorvos and pymetrozine (97 ± 1.22, 57 ± 3.1, respectively, p < 0.01), while abamectin and propargite had the highest mortality after four (44 ± 1.87 and 24 ± 2.91, respectively, p < 0.01) and eight (51 ± 2.91 and 17 ± 2.23, respectively, p < 0.01) days after spraying. At day 16th, post treatment, abamectin had the highest residual mortalities on O. albidipennis (15 ± 1.58, p < 0.01) and finally mortality results at the 20th day showed there is no significant difference between insecticides (p < 0.01).     

Increasing relevance of spring temperatures for Norway spruce trees in Davos,Switzerland, after the 1950s

Key message

Relevance of spring temperatures for tree-ring growth steadily increased since 1950s. Closely linked tree-ring growth and net CO ₂ exchange driven by spring temperatures.

Abstract

We investigated long-term (over 100 years) tree-ring width (TRW) variabilities as well as short-term (10 years) variations in net ecosystem productivity (NEP) in response to climate to assess the driving factors for stem growth of Norway spruce in a subalpine forest at Davos in Switzerland. A tree-ring width index (TRWi) chronology for the period from 1750 to 2006 was constructed and linked with climate data from 1876 to 2006, and with NEP available for the period from 1997 to 2006. Based on TRWi, we found that only two out of the 257 years exhibited extreme negative TRWi, compared to 29 years with extreme positive anomalies, observed mainly in recent decades. Annual temperature, annual precipitation, as well as autumn and winter temperature signals were well preserved in the TRWi chronology over the last 130 years. Spring temperatures became increasingly relevant for TRWi, explaining less than 1 % of the variation in TRWi for the period from 1876 to 2006, but 8 % for the period from 1950 to 2006 (p = 0.032), and even 47 % for 1997–2006 (p = 0.028). We also observed a strong positive relationship between annual TRWi and annual NEP (r = 0.661; p = 0.037), both strongly related to spring temperatures (r = 0.687 and r = 0.678 for TRWi and NEP, respectively; p = 0.028; p = 0.032). Moreover, we found strong links between monthly NEP of March and annual TRWi (r = 0.912; p = 0.0001), both related to March temperatures (r = 0.767, p = 0.010 and r = 0.724, p = 0.018, respectively). Thus, under future climate warming, we expect stem growth of these subalpine trees and also ecosystem carbon (C) sequestration to increase, as long as water does not become a limiting factor.     

Effects of shift work on attention deficit,hyperactivity, and impulsivity,and their relationship with chronotype

There is growing evidence that shift-work schedules cause severe disturbances to circadian rhythms and the sleep–wakefulness cycle, and that these changes in turn lead to cognitive and behavioral problems. The objective of this study is to explore the relationships between biological rhythm differences (chronotype) and impulsive behaviors and attention-deficit hyperactivity symptoms in shift workers. Seventy-nine nurses working in the daytime and 127 nurses working on night shifts were evaluated with the Barratt Impulsiveness Scale, Adult Attention Deficit Hyperactivity Disorder Self-Report Scale (ASRS), and Morningness–Eveningness questionnaire for identifying circadian preference. It was found that shift workers had more attention deficit (p < .05) and impulsivity (p < .01) when compared with daytime workers. Morning-type workers reported lower hyperactivity and ASRS total scores than evening- and intermediate-type workers. The mean impulsivity score of evening-type workers was higher than both the other groups (p < .05). It has been shown that attention deficit, hyperactivity, and impulsivity levels that appear as a result of working shifts might change in accordance with the individual’s chronotype. It might, therefore, be desirable to evaluate an individual’s chronotype to establish suitability for working shifts.     

Iron Availability Modulates the Response of Endosymbiotic Dinoflagellates to Heat Stress

Warming and nutrient limitation are stressors known to weaken the health of microalgae. In situations of stress, access to energy reserves can minimize physiological damage. Because of its widespread requirements in biochemical processes, iron is an important trace metal, especially for photosynthetic organisms. Lowered iron availability in oceans experiencing rising temperatures may contribute to the thermal sensitivity of reef‐building corals, which rely on mutualisms with dinoflagellates to survive. To test the influence of iron concentration on thermal sensitivity, the physiological responses of cultured symbiotic dinoflagellates (genus Breviolum; family Symbiodiniaceae) were evaluated when exposed to increasing temperatures (26 to 30°C) and iron concentrations ranging from replete (500 pM Fe’) to limiting (50 pM Fe’) under a diurnal light cycle with saturating radiance. Declines in photosynthetic efficiency at elevated temperatures indicated sensitivity to heat stress. Furthermore, five times the amount of iron was needed to reach exponential growth during heat stress (50 pM Fe′ at 26–28°C vs. 250 pM Fe′ at 30°C). In treatments where exponential growth was reached, Breviolum psygmophilum grew faster than B.minutum, possibly due to greater cellular contents of iron and other trace metals. The metal composition of B.psygmophilum shifted only at the highest temperature (30°C), whereas changes in B.minutum were observed at lower temperatures (28°C). The influence of iron availability in modulating each alga’s response to thermal stress suggests the importance of trace metals to the health of coral‐algal mutualisms. Ultimately, a greater ability to acquire scarce metals may improve the tolerance of corals to physiological stressors and contribute to the differences in performance associated with hosting one symbiont species over another.