Osteoclasts are specialized cells derived from the monocyte/macrophage haematopoietic lineage that develop and adhere to bone matrix, then secrete acid and lytic enzymes that degrade it in a specialized, extracellular compartment. Discovery of the RANK signalling pathway in the osteoclast has provided insight into the mechanisms of osteoclastogenesis and activation of bone resorption, and how hormonal signals impact bone structure and mass. Further study of this pathway is providing the molecular basis for developing therapeutics to treat osteoporosis and other diseases of bone loss.

Osteoclast differentiation and activation

Bevacizumab plus Irinotecan,Fluorouracil,and Leucovorin for Metastatic Colorectal Cancer

We describe the design, construction, and performance of the Sloan Digital Sky Survey telescope located at Apache Point Observatory. The telescope is a modified two-corrector Ritchey-Chretien design with a 2.5 m, f/2.25 primary, a 1.08 m secondary, a Gascoigne astigmatism corrector, and one of a pair of interchangeable highly aspheric correctors near the focal plane, one for imaging and the other for spectroscopy. The final focal ratio is f/5. The telescope is instrumented by a wide-area, multiband CCD camera and a pair of fiber-fed double spectrographs. Novel features of the telescope include the following: (1) A 3° diameter (0.65 m) focal plane that has excellent image quality and small geometric distortions over a wide wavelength range (3000-10,600 A) in the imaging mode, and good image quality combined with very small lateral and longitudinal color errors in the spectroscopic mode. The unusual requirement of very low distortion is set by the demands of time-delay-and-integrate (TDI) imaging. (2) Very high precision motion to support open-loop TDI observations. (3) A unique wind baffle/enclosure construction to maximize image quality and minimize construction costs. The telescope had first light in 1998 May and began regular survey operations in 2000.

https://iopscience.iop.org/article/10.1086/500975/pdf

The 2.5 m Telescope of the Sloan Digital Sky Survey

Catalytic protein subunits of telomerase from the ciliate Euplotes aediculatus and the yeast Saccharomyces cerevisiae contain reverse transcriptase motifs. Here the homologous genes from the fission yeast Schizosaccharomyces pombe and human are identified. Disruption of the S. pombe gene resulted in telomere shortening and senescence, and expression of mRNA from the human gene correlated with telomerase activity in cell lines. Sequence comparisons placed the telomerase proteins in the reverse transcriptase family but revealed hallmarks that distinguish them from retroviral and retrotransposon relatives. Thus, the proposed telomerase catalytic subunits are phylogenetically conserved and represent a deep branch in the evolution of reverse transcriptases.

https://science.sciencemag.org/content/sci/277/5328/955.full.pdf

Telomerase catalytic subunit homologs from fission yeast and human

Telomere Shortening and Tumor Formation by Mouse Cells Lacking Telomerase RNA

The dynamics of electron avalanche breakdown induced by picosecond laser pulses were observed directly with an ultrafast streak camera. The ionization rate for fused quartz exposed to a 25‐psec 532‐nm pulse which produced a damaging breakdown is ⩾4.5×1012 sec−1.

Direct observation of the dynamics of picosecond‐pulse optical breakdown

A new method of studying thermal-gradient-induced lensing in laser crystals is reported. The method is applied to an optically dense laser medium, ErTmHo:YAG, and the temporal behavior of the flash-lamp-pump-induced temperature distribution is determined during and after pumping. Data for high-repetition-rate pumping are also presented.

Method for temporally and spatially resolved thermal-lensing measurements.

BACKGROUND Men who have sex with men (MSM) are at high risk for human papillomavirus (HPV) infection and HPV-related anal cancer. Although a safe and effective vaccine is available to prevent HPV infection, HPV vaccine uptake among young MSM remains low. PURPOSE This pilot randomized controlled trial tested the acceptability, feasibility, and preliminary efficacy of a text messaging-based HPV vaccination intervention for young sexual minority men. METHODS In 2018, unvaccinated sexual minority men aged 18-25 years were recruited from Chicago to participate in a 9 month sexual health program called txt2protect. Participants (N = 150) were randomized to the intervention or control condition. Intervention condition messages focused primarily on HPV vaccination, with only a brief mention of other sexual health practices (e.g., condom use and HIV testing), while control condition messages focused on a variety of sexual health practices with only a brief mention of HPV vaccination. Participants received daily text messages for the first 3 weeks and monthly text messages for the remaining ~8 months of the trial. Participants completed surveys at baseline and 3 week and 9 month follow-ups. RESULTS Participants reported high satisfaction with the intervention. Although trial retention was high (with over 88% completing the 9 month survey), the study fell short of meeting its recruitment goal. HPV vaccine series initiation was significantly higher among intervention participants (19.4%) compared to control participants (6.6%), odds ratio = 3.43, 95% confidence interval: 1.17, 10.08. CONCLUSIONS Findings suggest that txt2protect is an acceptable and potentially promising intervention for increasing HPV vaccine initiation among young sexual minority men. CLINICAL TRIAL REGISTRATION NCT02994108.

Evaluation of a Text Messaging-Based Human Papillomavirus Vaccination Intervention for Young Sexual Minority Men: Results from a Pilot Randomized Controlled Trial

We have characterized non-critical phase-matching (NCPM) for both Type I and Type II second harmonic generation (SHG) in y-cut GdxY1−xCOB using a nanosecond optical parametric oscillator (OPO) The variation of the NCPM wavelength with temperature was investigated for different values of the compositional parameter x Efficient SHG of 1064 nm was achieved by choosing the suitable compositional parameter x = 028 and by tuning the temperature of the crystal to 52 ◦C Using a 25-mm-long Gd028Y072COB crystal, conversion efficiencies of 41 and 43% were obtained respectively from a mode-locked Nd : YAG and a Q-switched Nd : YAG laser

Non-critical phase-matched second harmonic generation in Gd x Y 1-x COB

A model is presented for analyzing volume Bragg gratings having large diffractive strength that may become distorted upon the passage of high-power laser light. One result of this analysis is that very little distortion in a volume Bragg grating can greatly reduce the reflectivity. This is a critical issue in the design of systems in which these devices are used to combine high-power laser beams.

Michael Bass

Papers

Direct observation of the dynamics of picosecond‐pulse optical breakdown

Method for temporally and spatially resolved thermal-lensing measurements.

Evaluation of a Text Messaging-Based Human Papillomavirus Vaccination Intervention for Young Sexual Minority Men: Results from a Pilot Randomized Controlled Trial

Non-critical phase-matched second harmonic generation in Gd x Y 1-x COB

Modeling the reflection of a laser beam by a deformed highly reflective volume bragg grating.