Tropical forests are thermally buffered despite intensive selective logging

Tropical rainforests are subject to extensive degradation by commercial selective logging. Despite pervasive changes to forest structure, selectively logged forests represent vital refugia for global biodiversity. The ability of these forests to buffer temperature-sensitive species from climate warming will be an important determinant of their future conservation value, although this topic remains largely unexplored. Thermal buffering potential is broadly determined by: (i) the difference between the "macroclimate" (climate at a local scale, m to ha) and the "microclimate" (climate at a fine-scale, mm to m, that is distinct from the macroclimate); (ii) thermal stability of microclimates (e.g. variation in daily temperatures); and (iii) the availability of microclimates to organisms. We compared these metrics in undisturbed primary forest and intensively logged forest on Borneo, using thermal images to capture cool microclimates on the surface of the forest floor, and information from dataloggers placed inside deadwood, tree holes and leaf litter. Although major differences in forest structure remained 9-12 years after repeated selective logging, we found that logging activity had very little effect on thermal buffering, in terms of macroclimate and microclimate temperatures, and the overall availability of microclimates. For 1°C warming in the macroclimate, temperature inside deadwood, tree holes and leaf litter warmed slightly more in primary forest than in logged forest, but the effect amounted to <0.1°C difference between forest types. We therefore conclude that selectively logged forests are similar to primary forests in their potential for thermal buffering, and subsequent ability to retain temperature-sensitive species under climate change. Selectively logged forests can play a crucial role in the long-term maintenance of global biodiversity

Temporal variation in abundance and diversity of butterflies in Bornean rain forests: opposite impacts of logging recorded in different seasons

We used traps baited with fruit to examine how the temporal variation of butterflies within primary forest in Sabah, Borneo differed between species. In addition, we compared patterns of temporal variation in primary and selectively logged forest, and we tested the hypothesis that selective logging has different recorded impacts on species diversity of adults during the wet monsoon period and the drier remaining half of the year. Species of Satyrinae and Morphinae had significantly less-restricted flight periods than did species of Nymphalinae and Charaxinae, which were sampled mainly during the drier season. especially in primary forest. Species diversity of adults was significantly higher during the drier season in primary forest, but did not differ between seasons in logged forest. As a consequence, logging had opposite recorded impacts on diversity during wetter and drier seasons: primary forest had significantly higher diversity than logged forest during the drier season but significantly lower diversity than logged forest during the wetter monsoon season. The results of this study have important implications for the assessment of biodiversity in tropical rain forests, particularly in relation to habitat disturbance: short-term assessments that do not take account of seasonal variation in abundance are likely to produce misleading results, even in regions where the seasonal variation in rainfall is not that great

The Antarctic Ozone Hole: An Update

The stratospheric ozone hole, an annual occurrence during austral spring, is caused by heterogeneous conversion of hydrogen chloride and chlorine nitrate to chlorine radicals. These reactions take place of polar stratospheric cloud particles in the cold, isolate Antarctic winter vortex. The chlorine radicals participate in chemical reactions that rapidly deplete ozone when sunlight returns at the end of polar night. International agreements eliminated production of the culprit anthropogenic chlorofluorocarbons in the late 1990s, but due to their long stratospheric lifetime (50-100 years), the ozone hole will continue its annual appearance for years to come

An Active Matrix Flat Panel Dosimeter (AMFPD) for inâ phantom dosimetric measurements

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135086/1/mp5012.pd

Laser frequency comb techniques for precise astronomical spectroscopy

Precise astronomical spectroscopic analyses routinely assume that individual pixels in charge-coupled devices (CCDs) have uniform sensitivity to photons. Intra-pixel sensitivity (IPS) variations may already cause small systematic errors in, for example, studies of extra-solar planets via stellar radial velocities and cosmological variability in fundamental constants via quasar spectroscopy, but future experiments requiring velocity precisions approaching ~1 cm/s will be more strongly affected. Laser frequency combs have been shown to provide highly precise wavelength calibration for astronomical spectrographs, but here we show that they can also be used to measure IPS variations in astronomical CCDs in situ. We successfully tested a laser frequency comb system on the Ultra-High Resolution Facility spectrograph at the Anglo-Australian Telescope. By modelling the 2-dimensional comb signal recorded in a single CCD exposure, we find that the average IPS deviates by <8 per cent if it is assumed to vary symmetrically about the pixel centre. We also demonstrate that series of comb exposures with absolutely known offsets between them can yield tighter constraints on symmetric IPS variations from ~100 pixels. We discuss measurement of asymmetric IPS variations and absolute wavelength calibration of astronomical spectrographs and CCDs using frequency combs.Comment: 11 pages, 7 figures. Accepted for publication in MNRA

Kajian tentang status kerintangan insektisid terhadap Plutella Xylostella, perosak utama sayur-sayuran Cruciferae di Kundasang, Sabah

Kajian ini dijalankan bertujuan untuk mengetahui status kerintangan insektisid terhadap larva Piute/la xylostella terhadap bahan aktif insektisid Cypermethrin, Spinosad, Avermectin, Chlorantraniliprole, Chlorfenapyr, Tolfenpyrad dan Lufenuron. Kajian ini telah dijalankan selama dua (2) tahun bermula pada tahun April 2013 - April 2015 menggunakan peruntukan Universiti Malaysia Sabah (SBK0136-STWN-2014). Tinjauan terhadap penggunaan insektisid oleh 40 responden yang mengusahakan ladang-ladang sayuran juga dilaksanakan bagi mengetahui hubungkait kerintangan insektisid dengan cara penggunaan insektisid di Kundasang. Kajian ini telah dilaksanakan di makmal dan ladang Fakulti Pertanian Lestari (FPL) UMS (Sandakan) yang merangkumi tiga peringkat iaitu i. penanaman kobis yang bebas dari serangan insektisid, ii. persampelan larva P. xylostella di Kundasang dan iii. ujian bioasai celup daun. Faktor Kerintangan Cypermethrin (FR > 160), Avamectin (FR > 10.1 - 40.0), Chlorantraniliprole (FR > 160) dan Chlofenapyr (FR > 160) adalah pada julat sederhana rintang hingga amat rintang. Cypermethrin dan Avamectin adalah bahan aktif insektisid yang telah direkodkan penggunaannya seawal tahun 1990an. Spinosad, Tolfenpyrad, Lufenuron, Chlorantraniliprol

Safety considerations for IMRT: Executive summary

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98742/1/MPH005067.pd

Island biogeography revisited: Museomics reveals affinities of shelf island birds determined by bathymetry and paleo-rivers, not by distance to mainland

Island biogeography is one of the most powerful subdisciplines of ecology: its mathematical predictions that island size and distance to mainland determine diversity have withstood the test of time. A key question is whether these predictions follow at a population-genomic level. Using rigorous ancient-DNA protocols, we retrieved ∼1000 genomic markers from ∼100 historic specimens of two Southeast Asian songbird complexes from across the Sunda Shelf archipelago collected 1893–1957. We show that the genetic affinities of populations on small shelf islands defy the predictions of geographic distance and appear governed by Earth-historic factors including the position of terrestrial barriers (paleo-rivers) and length of persistence of corridors (Quaternary land bridges). Our analyses suggest that classic island-biogeographic predictors may not hold well for population-genomic dynamics on the thousands of shelf islands across the globe, which are exposed to dynamic changes in land distribution during Quaternary climate change

Potential for doseâ escalation and reduction of risk in pancreatic cancer using IMRT optimization with lexicographic ordering and gEUDâ based cost functions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135067/1/mp6403.pd

Beyond counting climate consensus

Several studies have been using quantified consensus within climate science as an argument to foster climate policy. Recent efforts to communicate such scientific consensus attained a high public profile but it is doubtful if they can be regarded successful. We argue that repeated efforts to shore up the scientific consensus on minimalist claims such as ‘humans cause global warming’ are distractions from more urgent matters of knowledge, values, policy framing and public engagement.  Such efforts to force policy progress through communicating scientific consensus misunderstand the relationship between scientific knowledge, publics and policymakers. More important is to focus on genuinely controversial issues within climate policy debates where expertise might play a facilitating role. Mobilising expertise in policy debates calls for judgment, context and attention to diversity, rather than deferring to formal quantifications of narrowly scientific claims