Is hatching asynchrony beneficial for the brood?

Many hypotheses have been proposed to explain why female birdsstart to incubate before clutch completion (IBCC). Some of thosesuggest that the resulting hatching asynchrony (HA) is adaptivebecause it increases the size hierarchy among offspring andin turn reduces nestling competition and energy demands duringthe peak feeding period. Others argue that IBCC is a good strategyin unpredictable environments. When food conditions deteriorate,the large size hierarchy quickly results in the death of thelast hatched nestlings, allowing the remaining ones to surviveand fledge in better condition. In comparison, under favorableconditions, all nestlings can fledge independent of hatchingorder. To test these hypotheses, we performed a brood size manipulationexperiment (as a simulation of good and bad years) in collaredflycatchers Ficedula albicollis and examined the effect of sizehierarchy on offspring and brood performance. We found thatchicks with an initial size disadvantage experienced reducedbody mass growth and had shorter feathers at fledging in bothreduced and enlarged broods. In enlarged broods, they also fledgedwith a smaller skeletal size. Although broods on average orparents could possibly still benefit from HA when food is scarce,this was not seen in the current study. Parental survival wasnot related to the size hierarchy in the broods, and the averagebody mass growth of the nestlings was slower in broods witha high initial size variance. We therefore conclude that HAand the resulting size hierarchy are probably detrimental forthe growth of nestlings in both good and bad years, at leastin species where nestling mortality does not occur early inlife.     

Is fever beneficial?

Fever, the regulation of body temperature at an elevated level, is a common response to infection throughout the vertebrates, as well as in many species of invertebrate animals. It is probable that fever evolved as an adaptive response to infection hundreds of millions of years ago. Many components of the nonspecific and specific host response to infection are enhanced by small elevations in temperature. Perhaps more important, studies of bacterial- and viral-infected animals have shown that, in general, moderate fevers decrease morbidity and increase survival rate.     

Is elongation-induced leaf emergence beneficial for submerged Rumex species?

Background and Aims

Plant species from various taxa ‘escape’ from low oxygen conditions associated with submergence by a suite of traits collectively called the low oxygen escape syndrome (LOES). The expression of these traits is associated with costs and benefits. Thus far, remarkably few studies have dealt with the expected benefits of the LOES.

Methods

Young plants were fully submerged at initial depths of 450 mm (deep) or 150–240 mm (shallow). Rumex palustris leaf tips emerged from the shallow flooding within a few days, whereas a slight lowering of shallow flooding was required to expose R. acetosa leaf tips to the atmosphere. Shoot biomass and petiole porosity were measured for all species, and treatments and data from the deep and shallow submergence treatments were compared with non-flooded controls.

Key Results

R. palustris is characterized by submergence-induced enhanced petiole elongation. R. acetosa lacked this growth response. Upon leaf tip emergence, R. palustris increased its biomass, whereas R. acetosa did not. Furthermore, petiole porosity in R. palustris was twice as high as in R. acetosa.

Conclusions

Leaf emergence restores gas exchange between roots and the atmosphere in R. palustris. This occurs to a much lesser extent in R. acetosa and is attributable to its lower petiole porosity and therefore limited internal gas transport. Leaf emergence resulting from fast petiole elongation appears to benefit biomass accumulation if these plants contain sufficient aerenchyma in petioles and roots to facilitate internal gas exchange.Key words: Submergence, emergence, enhanced shoot elongation, porosity, aerenchyma, Rumex, cost–benefit analysis, phenotypic plasticity     

Is dietary restriction beneficial for human health, such as for immune function?

PURPOSE OF REVIEW: The impact of dietary restriction on physiologic function in humans is now beginning to be examined. The clinical trials are fueled by decades of animal experiments showing that dietary restriction delays the aging process and decreases the incidence of many age-associated diseases. The critical issue addressed in this article is whether or not dietary restriction long term is feasible or beneficial in humans. RECENT FINDINGS: Short-term dietary restriction in humans does appear to have beneficial effects at lowering metabolism, especially when examining carbohydrates and weight loss. Dietary restriction long term does, however, have detrimental psychological effects in humans, making its feasibility questionable. Even short-term dietary restriction can negatively impact physical activity and potentially some aspects of immunity. The best avenue for humans to benefit from dietary restriction would be for pharmacological or bioactive food ingredient mimetics to be developed which would be more applicable for long-term use. SUMMARY: Dietary restriction per se is unlikely to emerge as a feasible long-term strategy to improve human health. Developing dietary restriction mimetics targeting energy metabolism may prove beneficial, not only in aging, but also in diabetes and obesity.     

Is lycopene beneficial to human health?

Since humans cannot synthesise carotenoids de novo, we depend upon the diet exclusively for the source of these micronutrients. Although the necessity for beta-carotene, as the precursor of vitamin A has been recognised for many years, it is lycopene that has attracted substantial interest more recently. Lycopene is the red-coloured carotenoid predominantly found in tomato fruit, but in few other fruits or vegetables. It has claimed that it may alleviate chronic diseases such as cancers and coronary heart disease. This possibility has been studied extensively, by epidemiological studies and biochemical investigations of its properties and its bioavailability from tomato-based diets. This article summarises the current state of knowledge of the properties of lycopene, its possible role in human health and areas for future research.     

Is rotating between static and dynamic work beneficial for our fatigue state?

Shoulder disorders comprise a large part of work-related musculoskeletal disorders. Risk factors, such as repetitiveness and monotony, may cause muscle fatigue and be attenuated by task rotation. We investigated rotation between a dynamic box-lifting task and a relatively static pick-and-place task and aimed to determine whether (1) a high rotation frequency leads to less fatigue development than a low rotation frequency, and (2) a self-selected rotation frequency leads to less fatigue development than imposed rotation frequencies. Ten participants performed four one-hour rotation schedules: two low frequency rotation schedules rotating at 30 min, one high frequency rotation schedule rotating every sixth minute, and a self-selected rotation schedule. Borg, SOFI and electromyography of Trapezius and Deltoid subparts served as fatigue indicators. We found significant signs of fatigue for most schedules regarding the Borg and SOFI ratings and the M. Trapezius pars Descendens. Task rotation frequency had no significant effect on any of the outcome parameters, whereas the self-selected rotation schedule clearly resulted in less development of perceived fatigue than imposed schedules. In conclusion, we think that freedom of rotation has the greatest potential to attenuate potential development of musculoskeletal disorders and we require due caution with the use and interpretation of EMG indicators of fatigue.     

Are urban systems beneficial,detrimental, or indifferent for biological invasion?

Urban environments are often seen as unique or degraded habitats that both present hardships for some sensitive species and provide opportunities to others. Non-indigenous species (NIS) are commonly referenced in the latter group, and are comprised of species that can tolerate the unique conditions or capitalize on the opportunities found in urban environments. Moreover, these urban beneficiaries may be those that normally cannot overcome competitive interactions in intact native communities, but find opportunity to flourish in urban habitats. We ask the question: do NIS benefit from urbanization? We answer this question using three strategies. First, we explore the problem conceptually, using community assembly theory. Second, we perform a broad literature review. Finally, we analyze studies with sufficient information using a meta-analysis. We show that the available evidence supports the proposition that NIS benefit from urbanization, with NIS obtaining higher abundances and greater diversity in more urbanized habitats. There were only 43 studies that measured NIS abundance and diversity while adequately quantifying the degree of urbanization surrounding plots, and effect sizes (measured by Hedge’s D) reveal that NIS obtain higher abundances in more urbanized habitats, and especially for invertebrates. Despite the intense interest in NIS dynamics and impacts, we note a general dearth of robust studies that adequately quantify ‘urbanization’, and we end with a general call for more detailed research.     

Solar spectral lines ("solar halo")--healing or harmful for the retina?

The sungazing method has been known for thousands of years as healing method based on chromotherapeutic principle. Our examinations on the island of Rab show that it is acceptable only if applied 10 min before the sunset. Gazing has to be directed towards the green-yellow part of the spectrum, since the remaining part of the sun halo contains harmful energy. However, authors suggest that it would be preferable to use spectacles with medical filters transmitting wavelight of green-yellow colour, especially for treatment of macular degeneration.     

Invasive meningococcal disease and latex agglutination test — Is it still beneficial for diagnosis?

We showed current clinical usefulness of the latex agglutination (LA) test for confirmation of meningococcal etiology on 32 cerebrospinal fluid, 77 serum and 93 urine samples collected during the first week of hospitalization from 19 patients with laboratory confirmed invasive meningococcal disease. The positivity of the LA test in cerebrospinal fluid was 47%, in serum 42% and in urine 24%, while the PCR of cerebrospinal fluid and serum was positive in 95 and 47% cases, respectively. The latest positivity of the LA test was detected on day 2 in cerebrospinal fluid, on day 3 in serum and on day 4 in urine. In the group of patients who had received antibiotic therapy we found nonsignificant reduction of LA positivity and also statistically significant reduction of culture positivity in CSF (p = 0.04); the PCR positivity changed minimally. In blood samples, nonsignificant reduction of culture positivity and no difference in LA and PCR positivity was found. We did not find any statistically significant relationship between test results and clinical forms. The LA test can be therefore considered to be an auxiliary diagnostic method, rapid and easily practicable but less sensitive than PCR. It can be recommended especially for local laboratories where PCR is not available and the patient already received antibiotics before admission to the hospital.     

Furan fatty acids – Beneficial or harmful to health?

Furan fatty acids are found in plants, algae, and fish, and reported to have some positive health benefits, including anti-oxidant and anti-inflammatory activities, and inhibition of non-enzymatic lipid peroxidation. A major metabolite of furan fatty acids, 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), has been reported to be increased in patients who progress from prediabetes to type 2 diabetes, although CMPF is not necessarily associated with impaired glucose metabolism. Other studies report that CMPF levels are lower in subjects with diabetes than control subjects. Plasma CMPF levels increase in subjects who consume fish or fish oil, and in patients with renal failure. It is not known where furan fatty acids are converted to CMPF and it is speculated that this might be a result of microbiome activity. The plasma levels reported for CMPF in healthy, diabetic and patients with renal disease vary by factors of more than 100-fold within each of these three groups, so measurement error appears to be limiting the ability to interpret studies. This review explores these controversies and raises questions about whether CMPF is a marker for healthy diets or indeed associated with diabetes and renal health. The review concludes that, on balance, furan fatty acids are beneficial for health.     

Is sexual selection beneficial during adaptation to environmental change?

The role of sexual selection in adaptation is disputed. A balance between sexual and viability selection can be achieved in stable environments, but environmental perturbations could change the costs and benefits arising from sexual selection and influence the rate of adaptation. Here we synthesise theoretical and empirical work on the role of sexual selection in adaptation to changed conditions. Contrasting results have been gained, but the majority of studies suggest that sexual selection has no significant effect or a negative effect on the rate of adaptation. However, once sexually selected traits start to evolve, sexual selection can accelerate adaptation. The role of sexual selection in extinction appears to be minor, but the results could be skewed.     

Urocortin: a beneficial or detrimental agent to endothelium?

As a member of the corticotropin-releasing factor (CRF) family, urocortin (UCN) has been demonstrated to show diverse effects on cardiovascular system. It is commonly considered as a protective agent on vascular function. However, a growing body of evidence suggests that some effects of UCN may lead to endothelial dysfunction (ED) which may be the cause or consequence of vascular disease and a hallmark of known cardiovascular risk factors. The present review is then focused on recent evidence that reveals the beneficial and detrimental effects of UCN on endothelium.     

Pericentric inversions of chromosome number 9: benign or harmful?

Pericentric inversions of chromosome number 9 have been studied in 4 different probands: a normal female with designation 46,XX,inv(9)(p12q13); a male with Down syndrome designated as 47,XY,+21,inv(9))p13q13); a premature infant with multiple, congenital malformations who was 46,XX,inv(9)(p12q21), and a Down syndrome proband with 47,XYqs,+21,inv(9)(p13q21). All 4 cases were shown to be inherited based on family studies. These families are discussed with reference to the literature as to what possible effect this structural change could have on the reproductive capability of a normal carrier and what guidelines are available for counseling such a carrier.     

Single- or Pair-Housed: Which Is Better for Captive Southern Tamanduas?

The captive environment can limit some important behavioral options for nonhuman animals, which often results in decreased welfare. The companion of a conspecific can be a source of complexity in captivity, but this aspect has received little attention for solitary species. This study investigated the effects of two different housing conditions on the behavior of a solitary species, the Southern tamandua (Tamandua tetradactyla). Six individuals housed singly and four housed in pairs in two Brazilian zoological institutions were observed for 10 days from 09:00h to 17:00h during the rainy season. Each individual was observed for 26:40 hours. Compared with singly housed tamanduas, paired animals were less inactive (single = 74.62 ± 5.2%, paired = 28.51 ± 0.04% of the records), foraged and explored more (single = 11.07 ± 3.0%, paired 31.48 ± 0.01% of the records), and exhibited a diversity of behaviors 102.56% greater than single tamanduas. These results suggest that interactions with conspecifics in captivity, even for solitary animals, can promote the performance of desirable behaviors, which in several species has been correlated with improved welfare.