A case for 2-body material removal in prime LED sapphire substrate lapping and polishing

An alternative, and potentially better, means to process prime LED sapphire wafers is proposed. A brief history of material removal mechanisms suggests that brittle materials can be abraded in a ductile regime and that this can be a superior mode of removal. Advantages in material removal rate, surface finish and subsurface damage for a 2-body ductile removal of sapphire are shown relative to 3-body material removal. A major difficulty with this approach may be getting the LED manufacturing industry to understand that the appearance of the sapphire surface is quite different, unfamiliar yet predictable. Finally, some potential alternative process approaches are discussed that utilize 2-body material removal.     

Are white-crowned sparrow badges reliable signals?

Status badges, such as crown plumage, mediate intraspecific interactions. The reliability of crown morphology as a status badge in male mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) is uncertain. We examined morphological and physiological correlates of the proportion of crown that was white (“crown-white”) in 178 male mountain white-crowned sparrows during the 2008–2009 breeding seasons. Using a paired experimental design, we presented territory-holding males with white-enhanced and white-reduced decoys and recorded aggressive behaviors. To assess physiological constraints on signal bluffing, a subsample of birds was captured and released after manipulating natural crowns to simulate bluffed white-enhanced or white-reduced crowns; corticosterone concentrations were assayed from blood drawn upon recapture and after a restraint-induced stressor. We found a significant positive association between crown-white and a measure of body size—tarsus length—which is an established indicator of resource-holding potential. In the decoy challenge, males responded more aggressively toward white-enhanced than white-reduced decoys. In the hormone experiment, white-enhanced birds had higher baseline corticosterone levels, whereas white-reduced birds had similar concentrations to controls. Furthermore, white-enhanced birds had an attenuated restraint-induced corticosterone response, while white-reduced birds mounted a significantly larger increase in corticosterone than controls. Taken together, these findings indicate that crown-white is a reliable status badge of resource-holding potential in male mountain white-crowned sparrows during the breeding season.     

Endocrine disruptors in the Leça River and nearby Porto Coast (NW Portugal): presence of estrogenic compounds and hypoxic conditions

The Leça River and two beaches close to the north and south margins of the estuary, nowadays an important seaport harbor, show signs of contamination. However, the chemical nature of that contamination is uncertain. Therefore, this study checked for the presence of 11 endocrine disrupting compounds (EDCs) of animal (17β-estradiol and estrone), pharmaceutical (17α-ethynylestradiol), and industrial (alkylphenols, alkylphenol ethoxylates, and bisphenol A) origins in water samples collected from six points at the river gradient and at two sites in the coastline (Atlantic Ocean). Along with the EDCs, evaluated by gas chromatography – mass spectroscopy (GC-MS) during spring, summer, and autumn, physico-chemical parameters were also assessed and particular attention was given to dissolved oxygen (DO) levels. Data showed the presence of high amounts of estrogens (up to 10?ng?L^?1 for estrone) and industrial compounds (up to 2?µg?L^?1 for the nonylphenol ethoxylates) at both river and seacoast. Along with this, clear signs of hypoxia were found in the river (DO??1 at several sampling sites). Taking into account these issues, it was concluded that there are local conditions for the occurrence of endocrine disruption in aquatic animals.     

Colony take-over and brood survival in temporary social parasites of the ant genus Formica

Parasites reduce host fitness, and so instigate counter adaptations by their hosts. In temporary social parasitism, usurpers must not only enter the colony unharmed, but also have their eggs reared by the host workers. We introduced parasitic Formica lugubris and Formica aquilonia queens into queen right and orphaned fragments of three host species, Formica cinerea, Formica picea and Formica fusca, and show that workers of all three host species kill over 40 % of the introduced queens within 10 days, regardless of the presence/absence of a resident queen, and parasite species. More parasite queens died in F. cinerea than in F. picea and F. fusca. There were no major differences in survival between the parasite species (except that F. lugubris survived longer than F. aquilonia in F. fusca colonies compared to F. picea colonies), but parasite queens survived longer in orphaned than in queen right fragments of F. fusca. Experimental introduction of parasite (F. aquilonia) eggs into orphaned colonies of F. fusca showed that none of the parasite eggs were reared until pupation; whereas on average, 12 % of the con-specific hetero-colonial eggs introduced in the same manner were reared until pupation. In all colonies that received parasite brood, all offspring consisted of worker-laid males, whereas the corresponding value was 50 % for colonies that received con-specific hetero-colonial brood. Thus, when the risks of entering host colonies and brood failure are combined, the rate of successful colony take-over is very low. Moreover, the host workers can to some extent alleviate the costs of parasitism by producing a final batch of own offspring.     

Is there a different response to winds during migration between soaring and flapping raptors? An example with the Montagu’s harrier and the lesser kestrel

During migrations, birds have to cope with varying meteorological conditions, which shape their migratory routes and affect their performance. Amongst these, wind is the main meteorological agent influencing behaviour of birds in their migration journeys. Here we analyze the effect of winds during migrations of adult individuals of two raptor species tracked with satellite telemetry, the Montagu’s harrier (Circus pygargus) and the lesser kestrel (Falco naumanni). While harriers use mostly soaring flight, kestrels principally use flapping flight and thus, wind can differently affect these birds. We found that both forward and perpendicular winds significantly affected the movements of the Montagu’s harrier, which were drifted from their intended direction but also took advantage of tailwinds. On the contrary, lesser kestrels moved more regardless of forward winds, despite they were highly drifted by crosswinds. Our results also support that the drifting effect of winds at the onset of the spring migration may explain the loop migration observed for both species, with birds compensating later the effect of crosswinds to arrive to their breeding areas. Results presented here illustrate how winds can differently affect migrating birds according to their flight modes.     

Vigilance behaviour and fitness consequences: comparing a solitary foraging and an obligate group-foraging mammal

Vigilance behaviour in gregarious species has been studied extensively, especially the relationship between individual vigilance and group size, which is often negative. Relatively little is known about the effect of conspecifics on vigilance in non-obligate social species or the influence of sociality itself on antipredator tactics. We investigated predator avoidance behaviour in the yellow mongoose, Cynictis penicillata, a group-living solitary forager, and compared it with a sympatric group-living, group-foraging herpestid, the meerkat, Suricata suricatta. In yellow mongooses, the presence of conspecifics during foraging—an infrequent occurrence—reduced their foraging time and success and increased individual vigilance, contrary to the classical group-size effect. Comparing the two herpestids, sociality did not appear to affect overt vigilance or survival rates but influenced general patterns of predator avoidance. Whereas meerkats relied on communal vigilance, costly vigilance postures, and auditory warnings against danger, yellow mongooses avoided predator detection by remaining close to safe refuges and increasing “low-cost” vigilance, which did not interfere with foraging. We suggest that foraging group size in herpestids is constrained by species-distinct vigilance patterns, in addition to habitat and prey preference.     

Inventory of heavy metal content in organic waste applied as fertilizer in agriculture: evaluating the risk of transfer into the food chain

Background, aim, and scope  

In this work, an environmental risk assessment of reusing organic waste of differing origins and raw materials as agricultural fertilizers was carried out. An inventory of the heavy metal content in different organic wastes (i.e., compost, sludge, or manure) from more than 80 studies at different locations worldwide is presented.     

Ecosystem service provision,management systems and climate change in Valsaín forest,central Spain

This study addresses the impact of climate change and management approach on the provision of four ecosystem services (ES) (timber production, protection against gravitational hazards, carbon sequestration and biodiversity) in Valsaín forest in central Spain. The hybrid forest patch model PICUS v1.6 was used to simulate the development of 24 representative stand types over 100 years (2010–2110) in a full factorial simulation experiment combining three management regimes [“business as usual” management (BAU) and two alternatives to BAU (AM1 and AM2)], a no-management scenario (NOM) and six climate scenarios (historic climate represented by the period 1961–1990 and five transient climate change scenarios). Simulations indicated relatively small differences as regards the impact of the different management alternatives (BAU, AM1 and AM2) on the provision of ES as well as a clear improvement in biodiversity, protection and carbon storage under the no-management regime (NOM). Although timber production indicators were the most sensitive to climate change scenarios, biodiversity-related indicators responded fastest to the management regimes applied. Indicators of protection against rockfall and landslides were affected by both management and climate change. The results indicate substantial vulnerability of ES provisioning under the more extreme climate change scenarios at low elevations (1250 m). At higher elevations, the productivity of Scots pine stands may show a moderate decrease or increase, depending on the climate change scenario.     

<Emphasis Type="Italic">Mesorhizobium</Emphasis> bacterial strains isolated from the legume <Emphasis Type="Italic">Lotus corniculatus</Emphasis> are an alternative source for the production of polyhydroxyalkanoates (PHAs) to obtain bioplastics

Polyhydroxyalkanoic acids (PHAs) are natural polyesters that can be used to produce bioplastics which are biodegradable. Numerous microorganisms accumulate PHAs as energy reserves. Combinations of different PHAs monomers lead to the production of bioplastics with very different properties. In the present work, we show the capability of strains belonging to various phylogenetic lineages within the genus Mesorhizobium, isolated from Lotus corniculatus nodules, to produce different PHA monomers. Among our strains, we found the production of 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxydodecanoate, and 3-hydroxyhexadecanoate. Most of the PHA-positive strains were phylogenetically related to the species M. jarvisii. However, our findings suggest that the ability to produce different monomers forming PHAs is strain-dependent.     

Raw sugarcane bagasse as carbon source for xylanase production by Paenibacillus species: a potential degrader of agricultural wastes

Environmental Science and Pollution Research - Paenibacillus species isolated from a variety of natural sources have shown to be important glycoside hydrolases producers. These enzymes play a key...