Bow ties, metabolism and disease

Highly organized, universal structures underlying biological and technological networks mediate effective trade-offs among efficiency, robustness and evolvability, with predictable fragilities that can be used to understand disease pathogenesis. The aims of this article are to describe the features of one common organizational architecture in biology, the bow tie. Large-scale organizational frameworks such as the bow tie are necessary starting points for higher-resolution modeling of complex biologic processes     

Microbial flora on doctors' white coats.

OBJECTIVE--To determine the level and type of microbial contamination present on the white coats of doctors in order to assess the risk of transmission of pathogenic micro-organisms by this route in a hospital setting. DESIGN--Cross sectional survey of the bacterial contamination of white coats in a general hospital. SETTING--East Birmingham Hospital, an urban general hospital with 800 beds. SUBJECTS--100 doctors of different grades and specialties. RESULTS--The cuffs and pockets of the coats were the most highly contaminated areas. The level of bacterial contamination did not vary with the length of time a coat had been in use, but it increased with the degree of usage by the individual doctor. Staphylococcus aureus was isolated from a quarter of the coats examined, more commonly from those belonging to doctors in surgical specialties than medical specialties. Pathogenic Gram negative bacilli and other pathogenic bacteria were not isolated. CONCLUSIONS--White coats are a potential source of cross infection, especially in surgical areas. Scrupulous hand washing should be observed before and after attending patients and it may be advisable to remove the white coat and put on a plastic apron before examining wounds. There is little microbiological reason for recommending a more frequent change of white coat than once a week, nor for excluding the wearing of white coats in non-clinical areas.     

Field studies on inhibitory influence of skin pressure exerted by a body compensatory brassiere on the amount of feces

The present experiment investigated the effects of skin pressure produced by a body compensatory brassiere on defecation activity. Seven healthy females (11-41 yrs) volunteered as participants, being free of medication and constipation. The experiment lasted 3 weeks. The participants did not wear the body compensatory brassiere for the first week, wore it during waking hours for the second week, and again did not wear it for the third week. Whenever they desired to defecate, they did so and then weighted the amount of feces immediately by themselves. Eating times, daily amounts of foods and drinks, their menu, work intensity and its duration, retiring and rising time were controlled to be as similar as possible from day to day. The main finding was that the amount of feces was significantly smaller during the second week (wearing the body compensatory brassiere) than the first and third weeks (not wearing the body compensatory brassiere). These observations are discussed in terms of the suppression of the parasympathetic nervous system and intestine motility, and the delayed transit time in the large intestine.     

Modelling ties in the sign test

If ties occur in the sign test, the procedure recommended by Coakley and Heise (1996, Biometrics 52, 1242-1251) is the asymptotic uniformly most powerful nonrandomised test due to Putter (1955, Annals of Mathematical Statistics 26, 368-386). It may be shown that this is a consequence of how the probability of a tie is modelled. Other models with different optimal procedures can be constructed.     

Leaf ties as colonization sites for forest arthropods: an experimental study

Abstract.  1. Secondary colonization of leaf shelters constructed by caterpillars has been reported from a number of systems. Both the mechanism (larval or adult movement vs. oviposition) and the cues used by arthropods in locating leaf shelters, however, have received little attention.
2. Artificial leaf shelters (i.e. leaf ties or pairs of leaves clipped together to form sandwiches) were constructed on understorey white oak ( Quercus alba L.) trees and the abundance and species composition of arthropods colonizing and ovipositing on leaf pairs was examined in three treatments: occupied leaf ties (containing a leaf-tying caterpillar), unoccupied leaf ties, and non-tied control leaves.
3. The density of arthropods present in the occupied and unoccupied leaf ties after two weeks was seven and four times greater respectively, than non-tied controls. The guild composition of these early colonists differed among treatments, with the highest densities of leaf chewers, scavengers, and predators in occupied ties and the lowest densities in non-tied controls.
4. The densities of all arthropods ovipositing on leaf pairs in the occupied and unoccupied leaf tie treatments were four and three times greater than non-tied controls. Leaf-chewing insects (including leaf-tiers and non-tying inquiline species) and scavengers showed strong oviposition preferences for tied leaves. However, most species of leaf-tying caterpillars and the psocids (Psocoptera) did not distinguish between occupied and unoccupied ties, suggesting that these groups do not use occupancy-related cues in selecting oviposition sites.     

Making the connection: Latino immigrants and their cross-border ties

This paper uses the Pew Hispanic Center's 2006 National Survey of Latinos to study the everyday, routine cross-border activities of travel, remittance sending and telephone communication among Latin American immigrants in the United States. We ask how migrants vary in the intensity of their cross-border connections, distinguishing among the transmigrants, those captured by the host-country national social field, and those who maintain some ongoing home-country tie. We then examine the characteristics associated both with variations in the intensity of connectedness and with each specific type of connection. We show that most migrants maintain some degree of home-country connectedness, with a minority severing ties and a still smaller minority maintaining ties at a high degree of intensity. Connectivity is highly responsive to the location of key social ties, acculturation, and citizenship status, as well as the costs associated with the different types of cross-border activity.     

Seasonal population trend of the peach fruit fly (PFF), Bactrocera zonata (Saunders) (Diptera: Tephritidae), in Assiut,Northern Upper Egypt

The population of peach fruit fly during 2011 season increased gradually starting from the fourth week of July to reach its first major peak throughout the second week of September with 1340?flies/trap/day for traps suspended at 1?m height and during the third week of September with 909?flies/trap/day for traps hung at 2?m heights. Afterwards, the population trend showed a slight but gradual declining trend from the third week of September up to the third week of October. The population was then increased to reach its second major peak during the fourth week of October with 696 and 595?flies/trap/day for traps hung at 1 and 2?m heights, respectively. The greatest drop in the trapped population at both trap heights was observed from the second week of November until the end of the season (second week of December). A total of 105270?flies/trap at both 1 and 2?m trap heights during the entire seasons of 2011 were recorded. In 2012 season, the population followed nearly the same trend as that observed during 2011 season with minor variations. One major peak of abundance was recorded during the first week of October with 1344 and 955?flies/trap/day for traps hung at 1 and 2?m, respectively. The second major peak (1104 and 894?flies/trap/day) was observed during the fourth week of October for traps suspended at 1 and 2?m, respectively. A remarkable decrease in the population could be seen from the first week of December until the end of the season (fourth week of December). Statistical analysis of the data showed highly significant differences between fruit fly population captured at 1?m trap height (Mean = 446.9 ± 97?flies/trap/day) and that captured at 2?m trap heights (Mean = 321 ± 72?flies/trap/day) with paired t of 4.7^** and p-value of 0.0001^**.     

It's the recipient that counts: spending money on strong social ties leads to greater happiness than spending on weak social ties

Previous research has shown that spending money on others (prosocial spending) increases happiness. But, do the happiness gains depend on who the money is spent on? Sociologists have distinguished between strong ties with close friends and family and weak ties—relationships characterized by less frequent contact, lower emotional intensity, and limited intimacy. We randomly assigned participants to reflect on a time when they spent money on either a strong social tie or a weak social tie. Participants reported higher levels of positive affect after recalling a time they spent on a strong tie versus a weak tie. The level of intimacy in the relationship was more important than the type of relationship; there was no significant difference in positive affect after recalling spending money on a family member instead of a friend. These results add to the growing literature examining the factors that moderate the link between prosocial behaviour and happiness.     

Metabolism of Di- and Mono-n-Butyl Phthalate by Soil Bacteria

Samples for mycological analysis were collected from surfaces in the Skylab spacecraft before launch and during flight for each manned mission. Fungal contamination levels were low during the first two flights; however, the species recovered were different for each mission. On the third mission, widespread contamination of the Skylab spacecraft with Aspergillus and Pencillium spp. was detected. This contamination was traced to several contaminated space suit undergarments.     

AXONAL TRANSPORT OF SELECTED PARTICLE-SPECIFIC ENZYMES IN RAT SCIATIC NERVE IN VIVO AND ITS RESPONSE TO INJURY

Abstract— Orthograde and retrograde axoplasmic transport of selected axonal organelles were examined by monitoring accumulation of enzyme activities residing in various types of particles proximal and distal to a ligature placed on rat sciatic nerve as a function of time after tying. Proximal to the tie, activity of acetylcholinesterase (AChE, EC 3.1.1.7; probably in small endoplasmic reticulum-like particles) accumulated for 2 days; then, during the next 5 days, the accumulation disappeared. Activities of glutamic dehydrogenase (GDH, EC 1.4.1.3) and monoamine oxidase (MAO, EC 1.4.3.4) (both located in mitochondria) accumulated steadily for 7 days. Accumulation of monoamine oxidase activity was more rapid than that of glutamic dehydrogenase during the first day or two. Acid phosphatase (acid P'tase, EC 3.1.3.2; in lysosomes) activity also accumulated throughout the week of observation. Accumulation of all four enzyme activities proximal to the ligature was blocked by nerve crush or subepineurial vinblastine injection 1 cm or more proximal to the site of the tie. Distal to the ligature, AChE activity accumulated early (14 h), and then gradually disappeared in the course of the week. MAO activity also accumulated, with a maximum at 2 days, and no further change thereafter. GDH activity, on the other hand, showed little accumulation during the first 2 days, but did appear in modest amounts at the end of the week. Distal accumulation of acid P'tase kept pace with proximal accumulation for the first day, and continued more slowly for another day, after which there was no further change. This system has been used to study the effects of axonal crush injury upon anterograde and retrograde axoplasmic transport. A tie applied at various times after injury, proximal to the site of injury, was used to show that orthograde transport of AChE was maintained for 1 day after tying, but at 2 days had fallen 50% or more, and within a week was down to 20–25% of control. At 3 days after injury retrograde transport of AChE activity was not different from the control. Orthograde transport of acid P'tase activity was depressed 35% by injury. Retrograde transport of acid P'tase was inhibited more than 50% both at 3 and at 7 days after injury. Transport of the mitochondrial enzymes was not measurably affected.     

Turnaround of Axoplasmic Transport of Selected Particle-Specific Enzymes at an Injury in Control and Diisopropylphosphorofluoridate-Treated Rats

: Reversal of direction (turnaround) of axonal transport of particle specific enzyme activities was studied at a ligature placed on rat sciatic nerve. In the principal experiment, the ligature remained on the nerve in vivo several hours, allowing enzyme activities (acetylcholinesterase, acid phosphatase, and monoamine oxidase) to accumulate immediately proximal to the tie. The nerve was then tied a second time, proximal to the first tie, and incubated in vitro for several more hours. Accumulation of enzyme activities just distal to the second tie was measured. This second accumulation, of activities traveling in the retrograde direction, was shown to be the result of turnaround in several ways. (1) The increase in activity distal to the second tie was equal to the decrease in activity proximal to the first. (2) The increase in enzyme activities distal to the second tie was greatly reduced when the accumulation proximal to the first tie was trapped by placing a third tie between the first and second ties. (3) It was shown that the activity that accumulated distal to the second tie could not have been in retrograde motion at the time of the first tie. (4) Accumulation distal to the second tie was not a function of the length of nerve segment included between the two ties. In contrast to the consistent occurrence of turnaround of orthograde flow, turnaround of retrograde flow could not be demonstrated. Turnaround transport was blocked by incubation in the cold and in the presence of NaCN or vinblastine. The turnaround process operated on all three enzymes studied, suggesting that it operates on lysosomes and mitochondria, as well as on the endoplasmic reticulum-like material bearing acetylcholinesterase. Evidence for the participation of the transport process in the renewal of AChE in the distal portions of the axon was obtained in experiments using diisopropylphosphorofluoridate and cycloheximide.     

Effects of heavy metal stress on free amino acids in the haemolymph and proteins in haemolymph and total body tissue of Lymantria dispar larvae parasitized by Glyptapanteles liparidis

Heavy metal contamination of the forest pest insect Lymantria dispar (L.) (Lepidoptera; Lymantriidae), the gypsy moth, can alter its haemolymph composition, as has already been shown for carbohydrates and lipids in recent studies. L. dispar larvae are frequently parasitized by Glyptapanteles liparidis (Bouché) (Hymenoptera; Braconidae) larvae, which can—to some extent—regulate the population size of the pest insect. The parasitoids feed on the haemolymph of L. dispar larvae; hence, a different haemolymph composition of the host alters the trophic situation of the parasitoids. The aim of the present study was to investigate whether metal contamination also affects the concentrations of free amino acids in L. dispar haemolymph, and protein concentrations in their haemolymph and tissue. L. dispar larvae were parasitized on the first day of the second instar and then reared on diets contaminated with Cd, Pb, Cu or Zn at two concentrations each. Haemolymph and total body tissue of the larvae (fourth instar/third day) were analyzed. The concentrations of the free amino acids were elevated in five out of the eight contamination groups (Cd6, Pb4, Cu6, Cu10, Zn60), whereas haemolymph protein concentrations were significantly reduced in all contaminated individuals. The haemolymph protein concentration was 18 mg/ml in the control group and decreased to less than 10 mg/ml due to cadmium and zinc contamination at both concentrations and in the low copper contamination group. In contrast, total body proteins (136 g/mg dry weight in the control group) were elevated due to heavy metal stress. Analyses of haemolymph protein concentrations during the fourth instar demonstrated an increase of the proteins from day one to day four (followed by a decrease on the fifth day) in the control group and the cadmium contamination group. A steady increase of proteins from the first to the fifth day in the copper and zinc contaminated larvae indicated a retarded development in these groups. Thus, the present study along with other recent studies demonstrated, that heavy metal stress changes the concentrations of all main haemolymph compounds of L. dispar larvae.     

Glucocorticoid receptors in developing rat brain and liver

Dexamethasone receptors were measured by conventional equilibrium steroid binding studies in rat liver and brain cytosol, during late prenatal and postnatal development, Receptor binding could be detected in both cytosol preparations as early as the 17th day of gestation. Receptor levels in the cytosol from intact animals reached adult values by the 1st day after birth in both tissues. Using adrenalectomized animals an increase which reached adult values was observed during the first postnatal week for liver and the second postnatal week for brain. At physiological concentrations of endogenous glucocorticoids depletion of receptor from the cytosol of intact animals was minimal at postnatal day 1 and reached adult levels by day 7. chromatographie analysis in DEAE-Sephadex A50 minicolumns of unactivated and activated receptor constituents revealed the same pattern as that of adult animals. Glucocorticoid receptor complex from developing liver and brain was shown to be capable of binding to isolated adult liver nuclei after in vitro activation. However full capacity, for nuclear binding was observed in vivo, after injection of inducing doses of [³H]dexamethasone: By the end of the first week after birth adult nuclear binding capacity was observed in experiments in vivo while values peaked during the second week, in both tissues studied.     

Adverse changes in mood and cognitive performance of house officers after night duty.

The effects of long hours of work by junior doctors are the subject of growing concern. Experimental investigations of the effects of night duty on young doctors are few and have given inconclusive results. To measure the effects of long hours of work and reduced sleep on cognitive performance and mood 20 house officers (14 men and six women; mean age 25, range 24-35) were examined for 35 minutes in one session towards the end of a normal working day and in a second session at the same time after working for up to 31 continuous hours with reduced sleep. The order of the sessions was counterbalanced across the subjects. Each session comprised a series of cognitive tests: choice reaction time, vigilance reaction time, and haptic sorting tests and completion of a profile of mood states and a general questionnaire. After night duty there was a significant slowing in cognitive processing together with a decline in reaction times in the vigilance test. Loss of sleep contributed only to increased variability in the choice reaction time. Significant deleterious changes in mood after night duty occurred in all the mood scales after night duty. Continuous working may adversely affect the cognitive function and mood to the detriment of the welfare of doctors and their patients.     

Junior doctors' on call activities: differences in workload and work patterns among grades.

OBJECTIVE--To examine the workload and work patterns of junior doctors of all grades while on call. DESIGN--Pilot study of activity data self recorded by junior doctors, with the help of students during busy periods. SETTING--A general surgical firm and a general medical firm based at University Hospital, Nottingham. SUBJECTS--Four registrars, three senior house officers, and five preregistration house officers. RESULTS--Senior house officers and preregistration house officers spent nearly half of all their on call duty time working, but less than half of that time was spent in direct contact with patients. Registrars were on call more often than the house officers but spent less than one fifth of their on call duty time working, and almost two thirds of that time was spent in direct contact with patients. CONCLUSIONS--Workload while on duty is excessive for both senior and preregistration house officers. Changes in some administrative procedures and employment of more non-medical staff during on call periods might reduce the time spent on non-clinical activities, thereby reducing the overall workload and allowing more time for patient contact.     

S-(acetamidomethyl)mercapturic acid (AMMA): A new biomarker for occupational exposure to N,N-dimethylacetamide

N,N-dimethylacetamide (DMA) is used in the textile and plastics industry as a solvent alternative to more toxic N,N-dimethylformamide. Here we studied toxicokinetics of two major urinary metabolites of DMA, namely, S-(acetamidomethyl)mercapturic acid (AMMA) and N-methylacetamide (NMA). Urine samples were collected from workers exposed to DMA in a factory manufacturing acrylic fibers. AMMA and NMA were determined by HPLC/MS and GC/MS, respectively. The working scheme in the factory consisted of periods of three consecutive working shifts alternated regularly with two days off work. In the first stage of the study, NMA and AMMA were determined in urine samples collected before, in the middle, and at the end of one working shift. In the second stage, urine was collected five times during three consecutive days after a two-day rest: before and at the end of the first and second working shifts and before the third shift. It was found that the end-of-shift NMA levels were several folds higher than the pre-shift levels of the same day and dropped significantly until the next shift. On the other hand, there were no significant differences in AMMA levels before and at the end of the same shift but a continuous rise during the three-day working period was observed. Median values of NMA concentrations at the end of working shifts were between 10.1 and 17.3 mg/g creatinine, median AMMA concentrations in the second or third day of the working period varied between 12.4 and 38.1 mg/g creatinine. The approximate half-lives of NMA and AMMA (means) in the exposed workers were about 9 and 29 h, respectively. Thus, while NMA in the end-of-shift urine samples remains a preferential biomarker of DMA exposure during that shift, AMMA determined at the end of a work-week reflects cumulative exposure over the last few days. Further studies are needed to determine AMMA concentrations corresponding to the threshold limit value of DMA.     

Blood cells in rainbow trout Oncorhynchus mykiss milt: relation to milt collection method and sampling period

The presence of blood cells in milt of rainbow trout (Oncorhynchus mykiss) collected every week between the middle at the end of the spawning season, either by stripping or by catheterization was investigated. Basic sperm biological and biochemical characteristics were also evaluated. Because milt often becomes contaminated with blood during collection, we also studied the influence of experimental blood contamination on sperm motility and biochemical parameters of seminal plasma. We demonstrated the presence of blood cells (erythrocytes, lymphoid, and phagocytes) in rainbow trout milt collected by both methods. Both sampling period and collection method influenced sperm characteristics, however the relationship between these characteristics and blood cells are not clear at present. A high number of blood cells in milt was found in some samples, possibly due to inflammation, because at the same time we observed bacteria and elevated levels of protein and antiproteinase activity in contaminated samples. Experimental contamination of milt with blood did not influence sperm motility, protein concentration and LDH activity of the 5-day-stored semen. Our study demonstrated that blood cells were present in rainbow trout milt. Blood cells may also appear in milt as a result of bleeding and their elevated levels are present during inflammation.     

Transnational family ties of immigrants in the Netherlands

Inspired by recent efforts in the United States to quantify the degree of transnational ties that immigrants possess, this article explores and analyses the prevalence and determinants of transnational family ties of immigrants in the Netherlands. Using data from a representative survey of four immigrant groups in the Netherlands, this paper also aims to fill the gap in knowledge regarding the effects of incorporation into an immigrant's host society on transnational family ties. Findings show that, while the vast majority of immigrants with relatives in the country of origin have frequent contact with these relatives, only a third of respondents contribute to the livelihood of family members in the homeland. Incorporation characteristics show distinct patterns over different types of involvement. While incorporation variables have a negative effect on the frequency of contact, they show little effect on remittances.     

Insights on the Host Stress,Fear and Growth Responses to the Deoxynivalenol Feed Contaminant in Broiler Chickens

Mycotoxins pose an important danger to human and animal health. Poultry feeds are frequently contaminated with deoxynivalenol (DON) mycotoxin. It is thus of great importance to evaluate the effects of DON on the welfare related parameters in poultry industry. In the present study, the effects of contamination of broiler diet with 10 mg DON/kg feed on plasma corticosterone and heterophil to lymphocyte (H/L) ratio as indicators of stress, tonic immobility duration as an index for fear response and growth performance of broiler chickens were studied. In addition, the effect of a microbial feed additive either alone or in combination with DON contamination on these different aspects was also evaluated. The results showed that DON feeding significantly affected the welfare related parameters of broiler chickens. The feeding of DON contaminated diet resulted in an elevation of plasma corticosterone, higher H/L ratio and increased the fear levels as indicated by longer duration of tonic immobility reaction. Furthermore, DON reduced the body weight and body weight gain during the starter phase definitely at the second and third week. However, during grower phase, feeding of DON decreased the body weight at the fourth week and reduced the body gain at the fifth week. Addition of the microbial feed additive, a commercial antidote for DON mycotoxin, was able to overcome DON effects on stress index (H/L ratio), fearfulness and growth parameters of broilers. In conclusion, we showed for the first time that the DON feeding increased the underlying fearfulness and physiological stress responses of broilers and resulted in a reduction in the welfare status as indicated by higher plasma corticosterone, higher H/L ratio and higher fearfulness. Additionally, feeding the microbial feed additive was effective in reducing the adverse effects of DON on the bird''s welfare and can improve the performance of broiler chickens.     

A three-dimensional analysis of finger and bow string movements during the release in archery

The aim of this paper was to examine finger and bow string movements during archery by investigating a top Austrian athlete (FITA score = 1233) under laboratory conditions. Maximum lateral bow string deflection and angular displacements for index, third, and ring fingers between the full draw position and the end of the release were quantified using a motion tracking system. Stepwise multiple regression analyses were used to determine whether bow string deflection and finger movements are predictive for scoring. Joint ranges of motion during the shot itself were large in the proximal and distal interphalangeal joints, and much smaller in the metacarpophalangeal joints. Contrary to our expectations, greater deflection leads to higher scores (R2 = .18, p < .001) and the distal interphalangeal joint of the third finger weakly predicts the deflection (R2 = .11, p < .014). More variability in the joint angles of the third finger was found in bad shots than in good shots. Findings in this study let presume that maximum lateral bow string deflection does not adversely affect the archer's performance.