有關經濟重要的綠椿象研究

一九二六年春與孟夏，綠樁象Acanthocoris scabraton (F.)為害於燈籠果(Physolis Peruvigna L.)甚烈，時嶺南農科大學四年級生王君靄俊方以其生命史為「專題之研究」，余乃任指導之責焉。學期末，所育疑蛹尚未成虫，而王君須離校，余乃代畢其事。季夏，余復以此題授數學生，使之得養育昆虫之經驗。於是所得資料益豐。初，余擬於一九二七年夏再詳究其生命史，既以遠適他國，此事未果。但其後仍加種種之考察，所得雖未詳盡，然而畧記付刋似不容緩也

Photometry using the Infrared Array Camera on the Spitzer Space Telescope

We present several corrections for point source photometry to be applied to data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. These corrections are necessary because of characteristics of the IRAC arrays and optics and the way the instrument is calibrated in-flight. When these corrections are applied, it is possible to achieve a ~2% relative photometric accuracy for sources of adequate signal to noise in an IRAC image.Comment: 16 pages, 13 figures. Accepted for publication in the Publications of the Astronomical Society of the Pacifi

A disrupted circumstellar torus inside eta Carinae's Homunculus Nebula

We present thermal infrared images of the bipolar nebula surrounding eta Carinae at six wavelengths from 4.8 to 24.5 microns. These were obtained with the MIRAC3 camera system at the Magellan Observatory. Our images reveal new intricate structure in the bright core of the nebula, allowing us to re-evaluate interpretations of morphology seen in images with lower resolution. Complex structures in the core might not arise from a pair of overlapping rings or a cool (110 K) and very massive dust torus, as has been suggested recently. Instead, it seems more likely that the arcs and compact knots comprise a warm (350 K) disrupted torus at the intersection of the larger polar lobes. Some of the arcs appear to break out of the inner core region, and may be associated with equatorial features seen in optical images. The torus could have been disrupted by a post-eruption stellar wind, or by ejecta from the Great Eruption itself if the torus existed before that event. Kinematic data are required to rule out either possibility.Comment: 8 pages, 3 figures (Fig. 1 in color); to appear in ApJ Letter

Impaired β-glucocerebrosidase activity and processing in frontotemporal dementia due to progranulin mutations.

Loss-of-function mutations in progranulin (GRN) are a major autosomal dominant cause of frontotemporal dementia. Most pathogenic GRN mutations result in progranulin haploinsufficiency, which is thought to cause frontotemporal dementia in GRN mutation carriers. Progranulin haploinsufficiency may drive frontotemporal dementia pathogenesis by disrupting lysosomal function, as patients with GRN mutations on both alleles develop the lysosomal storage disorder neuronal ceroid lipofuscinosis, and frontotemporal dementia patients with GRN mutations (FTD-GRN) also accumulate lipofuscin. The specific lysosomal deficits caused by progranulin insufficiency remain unclear, but emerging data indicate that progranulin insufficiency may impair lysosomal sphingolipid-metabolizing enzymes. We investigated the effects of progranulin insufficiency on sphingolipid-metabolizing enzymes in the inferior frontal gyrus of FTD-GRN patients using fluorogenic activity assays, biochemical profiling of enzyme levels and posttranslational modifications, and quantitative neuropathology. Of the enzymes studied, only β-glucocerebrosidase exhibited impairment in FTD-GRN patients. Brains from FTD-GRN patients had lower activity than controls, which was associated with lower levels of mature β-glucocerebrosidase protein and accumulation of insoluble, incompletely glycosylated β-glucocerebrosidase. Immunostaining revealed loss of neuronal β-glucocerebrosidase in FTD-GRN patients. To investigate the effects of progranulin insufficiency on β-glucocerebrosidase outside of the context of neurodegeneration, we investigated β-glucocerebrosidase activity in progranulin-insufficient mice. Brains from Grn-/- mice had lower β-glucocerebrosidase activity than wild-type littermates, which was corrected by AAV-progranulin gene therapy. These data show that progranulin insufficiency impairs β-glucocerebrosidase activity in the brain. This effect is strongest in neurons and may be caused by impaired β-glucocerebrosidase processing

Role of Thalamic Projection in NMDA Receptor-Induced Disruption of Cortical Slow Oscillation and Short-Term Plasticity

NMDA receptor (NMDAR) antagonists, such as phencyclidine, ketamine, or dizocilpine (MK-801) are commonly used in psychiatric drug discovery in order to model several symptoms of schizophrenia, including psychosis and impairments in working memory. In spite of the widespread use of NMDAR antagonists in preclinical and clinical studies, our understanding of the mode of action of these drugs on brain circuits and neuronal networks is still limited. In the present study spontaneous local field potential (LFP), multi- (MUA) and single-unit activity, and evoked potential, including paired-pulse facilitation (PPF) in response to electrical stimulation of the ipsilateral subiculum were carried out in the medial prefrontal cortex (mPFC) in urethane anesthetized rats. Systemic administration of MK-801 (0.05 mg/kg, i.v.) decreased overall MUA, with a diverse effect on single-unit activity, including increased, decreased, or unchanged firing, and in line with our previous findings shifted delta-frequency power of the LFP and disrupted PPF (Kiss et al., 2011). In order to provide further insight to the mechanisms of action of NMDAR antagonists, MK-801 was administered intracranially into the mPFC and mediodorsal nucleus of the thalamus (MD). Microinjections of MK-801, but not physiological saline, localized into the MD evoked changes in both LFP parameters and PPF similar to the effects of systemically administered MK-801. Local microinjection of MK-801 into the mPFC was without effect on these parameters. Our findings indicate that the primary site of the action of systemic administration of NMDAR antagonists is unlikely to be the cortex. We presume that multiple neuronal networks, involving thalamic nuclei contribute to disrupted behavior and cognition following NMDAR blockade

Convergence of bark investment according to fire and climate structures ecosystem vulnerability to future change

Fire regimes in savannas and forests are changing over much of the world. Anticipating the impact of these changes requires understanding how plants are adapted to fire. Here we test whether fire imposes a broad selective force on a key fire-tolerance trait, bark thickness, across 572 tree species distributed worldwide. We show that investment in thick bark is a pervasive adaptation in frequently burned areas across savannas and forests in both temperate and tropical regions where surface fires occur. Geographic variability in bark thickness is largely explained by annual burned area and precipitation seasonality. Combining environmental and species distribution data allowed us to assess the vulnerability to future climate and fire conditions: tropical rainforests are especially vulnerable, whereas seasonal forests and savannas are more robust. The strong link between fire and bark thickness provides an avenue for assessing the vulnerability of tree communities to fire and demands inclusion in global models

Mechanisms Promoting the Long-Term Persistence of a Wolbachia Infection in a Laboratory-Adapted Population of Drosophila melanogaster

Intracellular bacteria of the genus Wolbachia are widespread endosymbionts across diverse insect taxa. Despite this prevalence, our understanding of how Wolbachia persists within populations is not well understood. Cytoplasmic incompatibility (CI) appears to be an important phenotype maintaining Wolbachia in many insects, but it is believed to be too weak to maintain Wolbachia in Drosophila melanogaster, suggesting that Wolbachia must also have other effects on this species. Here we estimate the net selective effect of Wolbachia on its host in a laboratory-adapted population of D. melanogaster, to determine the mechanisms leading to its persistence in the laboratory environment. We found i) no significant effects of Wolbachia infection on female egg-to-adult survival or adult fitness, ii) no reduced juvenile survival in males, iii) substantial levels of CI, and iv) a vertical transmission rate of Wolbachia higher than 99%. The fitness of cured females was, however, severely reduced (a decline of 37%) due to CI in offspring. Taken together these findings indicate that Wolbachia is maintained in our laboratory environment due to a combination of a nearly perfect transmission rate and substantial CI. Our results show that there would be strong selection against females losing their infection and producing progeny free from Wolbachia

Adaptive Optics Nulling Interferometric Constraints on the Mid-Infrared Exozodiacal Dust Emission around Vega

We present the results of mid-infrared nulling interferometric observations of the main-sequence star alpha Lyr (Vega) using the 6.5 m MMT with its adaptive secondary mirror. From the observations at 10.6 microns, we find that there is no resolved emission from the circumstellar environment (at separations greater than 0.8 AU) above 2.1% (3 sigma limit) of the level of the stellar photospheric emission. Thus, we are able to place an upper limit on the density of dust in the inner system of 650 times that of our own solar system's zodiacal cloud. This limit is roughly 2.8 times better than those determined with photometric excess observations such as those by IRAS. Comparison with far-infrared observations by IRAS shows that the density of warm dust in the inner system (< 30 AU) is significantly lower than cold dust at larger separations. We consider two scenarios for grain removal, the sublimation of ice grains and the presence of a planetary mass "sweeper." We find that if sublimation of ice grains is the only removal process, a large fraction (> 80%) of the material in the outer system is ice.Comment: 11 pages, 1 figure, Accepted to The Astrophysical Journal Letter