Comments on a Major Range Extension of the Little-Known Acrocera bakeri (Diptera: Acroceridae)

The spider fly Acrocera bakeri Coquillett, 1904 (Diptera: Acroceridae) is reported as a new state record for Wisconsin. This is a major range extension, because this rarely-encountered species was previously known only from the western U.S., specifically Arizona, California, and Nevada. The taxonomic history of the species is briefly discussed and hypotheses are offered for its unexpected presence in Wisconsin

The Host Galaxies of Fast-Ejecta Core-Collapse Supernovae

Spectra of broad-lined Type Ic supernovae (SN Ic-BL), the only kind of SN observed at the locations of long-duration gamma-ray bursts (LGRBs), exhibit wide features indicative of high ejecta velocities (~0.1c). We study the host galaxies of a sample of 245 low-redshift (z<0.2) core-collapse SN, including 17 SN Ic-BL, discovered by galaxy-untargeted searches, and 15 optically luminous and dust-obscured z<1.2 LGRBs. We show that, in comparison with SDSS galaxies having similar stellar masses, the hosts of low-redshift SN Ic-BL and z<1.2 LGRBs have high stellar-mass and star-formation-rate densities. Core-collapse SN having typical ejecta velocities, in contrast, show no preference for such galaxies. Moreover, we find that the hosts of SN Ic-BL, unlike those of SN Ib/Ic and SN II, exhibit high gas velocity dispersions for their stellar masses. The patterns likely reflect variations among star-forming environments, and suggest that LGRBs can be used as probes of conditions in high-redshift galaxies. They may be caused by efficient formation of massive binary progenitors systems in densely star-forming regions, or, less probably, a higher fraction of stars created with the initial masses required for a SN Ic-BL or LGRB. Finally, we show that the preference of SN Ic-BL and LGRBs for galaxies with high stellar-mass and star-formation-rate densities cannot be attributed to a preference for low metal abundances but must reflect the influence of a separate environmental factor.Comment: Accepted by ApJ 9 May 2014 with only minor revision

Endoscopic endonasal management of recurrent petrous apex cholesterol granuloma.

Petrous apex cholesterol granulomas (PACG) are uncommon lesions. Recurrence following transcranial or endonasal approaches to aerate the cyst occurs in up to 60% of cases. We describe the technical nuances pertinent to the endonasal endoscopic management of a recurrent symptomatic PACG and review the literature. A 19-year-old woman presented with a recurrent right abducens nerve paresis. Four months prior, she underwent an endonasal transsphenoidal surgery (TSS) for drainage of a symptomatic PACG. Current imaging documented recurrence of the right PACG. Transsphenoidal and infrapetrous approaches were performed to obtain a wider bony opening along the petrous apex and drain the cyst. A Doyle splint was inserted into the cyst's cavity and extended out into the sphenoid, maintaining patency during the healing process. Three months after surgery, the splint was removed endoscopically, allowing visualization of a patent cylindrical communication between both aerated cavities. The patient remains symptom- and recurrence-free. Endoscopic endonasal surgery must be adapted to manage recurrent PACG. A TSS may not be sufficient. An infrapetrous approach with wider bony opening, extensive removal of the cyst's anterior wall, and use of a stent are indicated for the treatment of recurrent PACG and to prevent recurrences

Arceuthobium campylopodum Engelm.

https://thekeep.eiu.edu/herbarium_specimens_byname/20777/thumbnail.jp

Arceuthobium campylopodum Engelm.

https://thekeep.eiu.edu/herbarium_specimens_byname/20777/thumbnail.jp

Reduced Specificity of Hippocampal and Posterior Ventrolateral Prefrontal Activity during Relational Retrieval in Normal Aging

Neuroimaging studies of episodic memory in young adults demonstrate greater functional neural activity in ventrolateral pFC and hippocampus during retrieval of relational information as compared with item information. We tested the hypothesis that healthy older adults—individuals who exhibit behavioral declines in relational memory—would show reduced specificity of ventrolateral prefrontal and hippocampal regions during relational retrieval. At study, participants viewed two nouns and were instructed to covertly generate a sentence that related the words. At retrieval, fMRIs were acquired during item and relational memory tasks. In the relational task, participants indicated whether the two words were previously seen together. In the item task, participants indicated whether both items of a pair were previously seen. In young adults, left posterior ventrolateral pFC and bilateral hippocampal activity was modulated by the extent to which the retrieval task elicited relational processing. In older adults, activity in these regions was equivalent for item and relational memory conditions, suggesting a reduction in ventrolateral pFC and hippocampal specificity with normal aging.Psycholog

NPAS4 recruits CCK basket cell synapses and enhances cannabinoid-sensitive inhibition in the mouse hippocampus.

Experience-dependent expression of immediate-early gene transcription factors (IEG-TFs) can transiently change the transcriptome of active neurons and initiate persistent changes in cellular function. However, the impact of IEG-TFs on circuit connectivity and function is poorly understood. We investigate the specificity with which the IEG-TF NPAS4 governs experience-dependent changes in inhibitory synaptic input onto CA1 pyramidal neurons (PNs). We show that novel sensory experience selectively enhances somatic inhibition mediated by cholecystokinin-expressing basket cells (CCKBCs) in an NPAS4-dependent manner. NPAS4 specifically increases the number of synapses made onto PNs by individual CCKBCs without altering synaptic properties. Additionally, we find that sensory experience-driven NPAS4 expression enhances depolarization-induced suppression of inhibition (DSI), a short-term form of cannabinoid-mediated plasticity expressed at CCKBC synapses. Our results indicate that CCKBC inputs are a major target of the NPAS4-dependent transcriptional program in PNs and that NPAS4 is an important regulator of plasticity mediated by endogenous cannabinoids

Exceptional Collections for Mirrors of Invertible Polynomials

We prove the existence of a full exceptional collection for the derived category of equivariant matrix factorizations of an invertible polynomial with its maximal symmetry group. This proves a conjecture of Hirano--Ouchi. In the Gorenstein case, we also prove a stronger version of this conjecture due to Takahashi. Namely, that the full exceptional collection is strong.Comment: 14 pages, Counterexample retracted thanks to K. Ueda. References adde

A maximally-graded invertible cubic threefold that does not admit a full exceptional collection of line bundles

We show that there exists a cubic threefold defined by an invertible polynomial that, when quotiented by the maximal diagonal symmetry group, has a derived category which does not have a full exceptional collection consisting of line bundles. This provides a counterexample to a conjecture of Lekili and Ueda.Comment: 8 pages, minor revision, to appear in Forum of Math, Sigm