The "Forcipomyia ingrami" Complex in Hawaii (Diptera: Ceratopogonidae)

Biting midges of the genus Forcipomyia are some of the most important pollinators of cacao and other tropical crop plants. A study of the species known as F. ingrami revealed that it has been misidentified, and that the African species formerly known as ingrami, now psilonota, does not occur in Hawaii. Instead there are at least four other species: palikuensis Hardy, a large, shining blackish species from Hawaii and East Maui; kaneohe n. sp., a small shining species from Oahu; pholeter n. sp., a small pale species living in lava tube caves on Hawaii; and hardyi n. sp., a dull brownish species which is extremely common on all the islands; all probably endemic to the Hawaiian Islands. The immature stages of these midges, which breed in wet, decaying vegetation, leaf axils, and aquatic vegetation, have excellent characters diagnostic for species. Characters are illustrated and discussed showing how these species may be distinguished from their closely related congeners from the Pacific, Asia, and Africa. Forcipomyia clara Chan and LeRoux from Singapore is a junior synonym of F. sauteri Kieffer (N. SYNONYMY)

New State Records and Additions to the Alien Terrestrial Arthropod Fauna in the Hawaiian Islands

An annotated list of 393 adventive terrestrial arthropod species plus three new varieties of known established species, which have been recorded in Hawaii since the Fourth Edition of Bishop Museum’s Hawaiian Terrestrial Arthro- pod Checklist (Nishida 2002), is presented. This compilation includes records of over 362 nonnative arthropod species published between the years of 2001 and 2017 as well as over 30 new Hawaii State records that have not been previously recorded. Annotations include date first detected, island distribution, citation, relevant biological notes, and for new state and island records, the collection data. A separate table with about 150 entries lists the synonyms, misidentifications, dele- tions, and changes of status for species included in the 2002 checklist that were discovered during our research. However, the latter list is not comprehensive as a complete revision of the 2002 checklist was beyond the scope of our project. Also included is a bibliography of the approximately 270 source documents that were consulted. We intend for this publication to be a useful supplement to the 2002 edition of the Hawaiian Terrestrial Arthropod Checklist

Role of external inputs of nutrients to aquatic ecosystems in determining prevalence of nitrogen vs. phosphorus limitation of net primary productivity

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Howarth, R. W., Chan, F., Swaney, D. P., Marino, R. M., & Hayn, M. Role of external inputs of nutrients to aquatic ecosystems in determining prevalence of nitrogen vs. phosphorus limitation of net primary productivity. Biogeochemistry, (2021), https://doi.org/10.1007/s10533-021-00765-z.Whether net primary productivity in an aquatic ecosystem is limited by nitrogen (N), limited by phosphorus (P), or co-limited by N & P is determined by the relative supply of N and P to phytoplankton compared to their elemental requirements for primary production, often characterized by the “Redfield” ratio. The supply of these essential nutrients is affected by both external inputs and biogeochemical processes within the ecosystem. In this paper, we examine external sources of nutrients to aquatic systems and how the balance of N to P inputs influences nutrient limitation. For ocean subtropical gyres, a relatively balanced input of N and P relative to the Redfield ratio from deep ocean sources often leads to near co-limitation by N and P. For lakes, the external nutrient inputs come largely from watershed sources, and we demonstrate that on average the N:P ratio for these inputs across the United States is well above that needed by phytoplankton, which may contribute to P limitation in those lake that experience this average nutrient loading. Watershed inputs are also important for estuaries and coastal marine ecosystems, but ocean sources of nutrients are also significant contributors to overall nutrient loads. The ocean-nutrient sources of N and P are very often at or below the Redfield ratio of 16:1 molar, and can be substantially so, particularly in areas where the continental shelf is wide. This large input of coastal ocean nutrients with a low N:P ratio is one factor that may make N limitation more likely in many coastal marine ecosystems than in lakes.Preparation of this manuscript was supported by a National Science Foundation Grant # 1654845 from the Long Term Research in Environmental Biology program, a grant from the Atkinson Center for a Sustainable Future at Cornell University, and by an endowment given to Cornell by David R. Atkinson to support a professorship held by RWH

Enhanced cerebral blood volume under normobaric hyperoxia in the J20-hAPP mouse model of Alzheimer’s disease

Early impairments to neurovascular coupling have been proposed to be a key pathogenic factor in the onset and progression of Alzheimer’s disease (AD). Studies have shown impaired neurovascular function in several mouse models of AD, including the J20-hAPP mouse. In this study, we aimed to investigate early neurovascular changes using wild-type (WT) controls and J20-hAPP mice at 6 months of age, by measuring cerebral haemodynamics and neural activity to physiological sensory stimulations. A thinned cranial window was prepared to allow access to cortical vasculature and imaged using 2D-optical imaging spectroscopy (2D-OIS). After chronic imaging sessions where the skull was intact, a terminal acute imaging session was performed where an electrode was inserted into the brain to record simultaneous neural activity. We found that cerebral haemodynamic changes were significantly enhanced in J20-hAPP mice compared with controls in response to physiological stimulations, potentially due to the significantly higher neural activity (hyperexcitability) seen in the J20-hAPP mice. Thus, neurovascular coupling remained preserved under a chronic imaging preparation. Further, under hyperoxia, the baseline blood volume and saturation of all vascular compartments in the brains of J20-hAPP mice were substantially enhanced compared to WT controls, but this effect disappeared under normoxic conditions. This study highlights novel findings not previously seen in the J20-hAPP mouse model, and may point towards a potential therapeutic strategy

The KX method for producing K-band flux-limited samples of quasars

The longstanding question of the extent to which the quasar population is affected by dust extinction, within host galaxies or galaxies along the line of sight, remains open. More generally, the spectral energy distributions of quasars vary significantly and flux-limited samples defined at different wavelengths include different quasars. Surveys employing flux measurements at widely separated wavelengths are necessary to characterise fully the spectral properties of the quasar population. The availability of panoramic near-infrared detectors on large telescopes provides the opportunity to undertake surveys capable of establishing the importance of extinction by dust on the observed population of quasars. We introduce an efficient method for selecting K-band, flux-limited samples of quasars, termed ``KX'' by analogy with the UVX method. This method exploits the difference between the power-law nature of quasar spectra and the convex spectra of stars: quasars are relatively brighter than stars at both short wavelengths (the UVX method) and long wavelengths (the KX method). We consider the feasibility of undertaking a large-area KX survey for damped Ly-alpha galaxies and gravitational lenses using the planned UKIRT wide-field near-infrared camera.Comment: 6 pages, 3 figures, to appear in MNRA

Coupled biogeochemical cycles : eutrophication and hypoxia in temperate estuaries and coastal marine ecosystems

Author Posting. © Ecological Society of America, 2011. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 9 (2011): 18–26, doi:10.1890/100008.Nutrient fluxes to coastal areas have risen in recent decades, leading to widespread hypoxia and other ecological damage, particularly from nitrogen (N). Several factors make N more limiting in estuaries and coastal waters than in lakes: desorption (release) of phosphorus (P) bound to clay as salinity increases, lack of planktonic N fixation in most coastal ecosystems, and flux of relatively P-rich, N-poor waters from coastal oceans into estuaries. During eutrophication, biogeochemical feedbacks further increase the supply of N and P, but decrease availability of silica – conditions that can favor the formation and persistence of harmful algal blooms. Given sufficient N inputs, estuaries and coastal marine ecosystems can be driven to P limitation. This switch contributes to greater far-field N pollution; that is, the N moves further and contributes to eutrophication at greater distances. The physical oceanography (extent of stratification, residence time, and so forth) of coastal systems determines their sensitivity to hypoxia, and recent changes in physics have made some ecosystems more sensitive to hypoxia. Coastal hypoxia contributes to ocean acidification, which harms calcifying organisms such as mollusks and some crustaceans.Funding was supplied in part by NOAA through the Coastal Hypoxia Research Program, by the NSF through the Biocomplexity Coupled Biogeochemical Cycles competition, and by DR Atkinson through an endowment given to Cornell University

Shale gas production: potential versus actual greenhouse gas emissions

Estimates of greenhouse gas (GHG) emissions from shale gas production and use are controversial. Here we assess the level of GHG emissions from shale gas well hydraulic fracturing operations in the United States during 2010. Data from each of the approximately 4000 horizontal shale gas wells brought online that year are used to show that about 900 Gg CH[subscript 4] of potential fugitive emissions were generated by these operations, or 228 Mg CH[subscript 4] per well—a figure inappropriately used in analyses of the GHG impact of shale gas. In fact, along with simply venting gas produced during the completion of shale gas wells, two additional techniques are widely used to handle these potential emissions: gas flaring and reduced emission 'green' completions. The use of flaring and reduced emission completions reduce the levels of actual fugitive emissions from shale well completion operations to about 216 Gg CH[subscript 4], or 50 Mg CH[subscript 4] per well, a release substantially lower than several widely quoted estimates. Although fugitive emissions from the overall natural gas sector are a proper concern, it is incorrect to suggest that shale gas-related hydraulic fracturing has substantially altered the overall GHG intensity of natural gas production

On the nature of the red, 2MASS-selected AGN in the local Universe I: an optical spectroscopic study

We present optical spectra for a representative sample of 27 nearby (z < 0.2) Two Micron All Sky Survey (2MASS)-selected active galactic nuclei (AGN) with red near-infrared colours (J − KS ≳ 2.0). The spectra were taken with the ISIS spectrograph on the William Herschel Telescope with the aim of determining the nature of the red 2MASS AGN, in particular whether they are young quasars obscured by their natal cocoons of gas and dust. We compare our findings with those obtained for comparison samples of PG quasars and unobscured type 1 AGN. The spectra show a remarkable variety, including moderately reddened type 1 objects (45 per cent), type 1 objects that appear similar to traditional ultraviolet (UV)-/optical-selected AGN (11 per cent), narrow-line type 1 Seyfert AGN (15 per cent), type 2 AGN (22 per cent) and H II/composite objects (7 per cent). The high Balmer decrements that we measure in many of the type 1 objects are consistent with their red J − KS colours being due to moderate levels of dust extinction (0.2 < E(B − V) < 1.2). However, we measure only modest velocity shifts and widths for the broader [O III]λ5007 emission-line components that are similar to those measured in the comparison samples. This suggests that the outflows in the red 2MASS objects are not unusual compared with those of optical-/UV-selected AGN of similar luminosity. In addition, the Eddington ratios for the 2MASS sample are relatively modest. Overall, based on their optical spectra, we find no clear evidence that the population of red, 2MASS-selected AGN at low redshifts represents young quasars. Most plausibly, these objects are normal type 1 AGN that are moderately obscured by material in the outer layers of the circumnuclear tori or in the discs of the host galaxies

Mapping interactions with the chaperone network reveals factors that protect against tau aggregation.

A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease