The journal’s the thing: teaching natural history and nature writing in Baja California Sur

The skills of making informed observations, synthesizing those observations, and communicating them effectively are central to the naturalist. Developing university courses that optimize instruction in these skills simultaneously can, however, be a challenge. Here we describe a program at Santa Clara University comprised of two integrated co-requisite courses, Writing Natural History (ENVS 142) and The Natural History of Baja (BIOL/ENVS 144). Lectures through the 10-week winter quarter expand students’ knowledge of the ecosystems and biodiversity of the Baja Peninsula and help them to develop descriptive writing skills. The courses culminate in a ten-day expedition to the Baja Peninsula and Isla Espiritu Santo in the Sea of Cortez, where students explore local ecosystems and journal about their experiences. The result is a program in which students expand their skills in natural history and develop their own voices as writers and natural historians. We describe the structure and philosophy of this program and provide details on associated lecture topics, logistics, exercises, and readings

Estimation of Effective Lens Position Using a Method Independent of Preoperative Keratometry Readings

Purpose To evaluate the validity of a keratometry (K)-independent method of estimating effective lens position (ELP) before phacoemulsification cataract surgery. Setting Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland. Design Evaluation of diagnostic test or technology. Methods The anterior chamber diameter and corneal height in eyes scheduled for cataract surgery were measured with a rotating Scheimpflug camera. Corneal height and anterior chamber diameter were used to estimate the ELP in a K-independent method (using the SRK/T [ELPrs] and Holladay 1 [ELPrh] formulas). Results The mean ELP was calculated using the traditional (mean ELPs 5.59 mm ± 0.52 mm [SD]; mean ELPh 5.63 ± 0.42 mm) and K-independent (mean ELPrs 5.55 ± 0.42 mm; mean ELPrh ± SD 5.60 ± 0.36 mm) methods. Agreement between ELPs and ELPrs and between ELPh and ELPrh were represented by Bland-Altman plots, with mean differences (± 1.96 SD) of 0.06 ± 0.65 mm (range −0.59 to +0.71 mm; P=.08) in association with ELPrs and −0.04 ± 0.39 mm (range −0.43 to +0.35 mm; P=.08) in association with ELPrh. The mean absolute error for ELPs versus ELPrs estimation and for ELPh versus ELPrh estimation was 0.242 ± 0.222 mm (range 0.001 to 1.272 mm) and 0.152 ± 0.137 mm (range 0.001 to 0.814 mm), respectively. Conclusion This study confirms that the K-independent ELP estimation method is comparable to traditional K-dependent methods and may be useful in post-refractive surgery patients

Transport and Retinal Capture of Lutein and Zeaxanthin with Reference to age-Related Macular Degeneration.

Abstract. Age-related macular degeneration (AMD) is the most common cause of irreversible blindness in the elderly population in the western world. The etiology and pathogenesis of this disease remain unclear. However, there is an increasing body of evidence supporting the hypothesis that the macular pigment carotenoids, lutein and zeaxanthin, play an important role in protection against AMD, by filtering out blue light at a pre-receptoral level, or by quenching free radicals. Lutein and zeaxanthin are dietary zanthophyll carotenoids, which are delivered to the retina via plasma lipoproteins. The biological mechanisms governing retinal capture and accumulation of lutein and zeaxanthin, to the exclusion of other carotenoids, are still poorly understood. Although these mechanisms remain unclear, it is possible that selective capture of these carotenoids is related to lipoprotein, apolipoprotein, function and profile. Xanthophyll-blinding proteins appear to play an important role in the retinal capture of the xanthophyll carotenoids. The Pi isoform of GSTP1 has been isolated as a specific binding protein for zeaxanthin. The binding protein responsible for retinal uptake of lutein remains elusive. This article reviews the literature germane to the mechanisms involved in the capture, accumulation and stabilization of lutein and zeaxanthin by the retina, and the processes nvolvedin their transport in serum

Multiwavelength Transit Observations of the Candidate Disintegrating Planetesimals Orbiting WD 1145+017

We present multiwavelength, multi-telescope, ground-based follow-up photometry of the white dwarf WD 1145+017, that has recently been suggested to be orbited by up to six or more, short-period, low-mass, disintegrating planetesimals. We detect 9 significant dips in flux of between 10% and 30% of the stellar flux from our ground-based photometry. We observe transits deeper than 10% on average every ~3.6 hr in our photometry. This suggests that WD 1145+017 is indeed being orbited by multiple, short-period objects. Through fits to the multiple asymmetric transits that we observe, we confirm that the transit egress timescale is usually longer than the ingress timescale, and that the transit duration is longer than expected for a solid body at these short periods, all suggesting that these objects have cometary tails streaming behind them. The precise orbital periods of the planetesimals in this system are unclear from the transit-times, but at least one object, and likely more, have orbital periods of ~4.5 hours. We are otherwise unable to confirm the specific periods that have been reported, bringing into question the long-term stability of these periods. Our high precision photometry also displays low amplitude variations suggesting that dusty material is consistently passing in front of the white dwarf, either from discarded material from these disintegrating planetesimals or from the detected dusty debris disk. For the significant transits we observe, we compare the transit depths in the V- and R-bands of our multiwavelength photometry, and find no significant difference; therefore, for likely compositions the radius of single-size particles in the cometary tails streaming behind the planetesimals in this system must be ~0.15 microns or larger, or ~0.06 microns or smaller, with 2-sigma confidence.Comment: 16 pages, 12 figures, submitted to ApJ on October 8th, 201

The relationship between macular pigment optical density and its constituent carotenoids in diet and serum

PURPOSE: Lutein (L) and zeaxanthin (Z) are two dietary carotenoids that accumulate at the macula, where they are collectively known as macular pigment (MP). There is a biologically plausible rationale, with some supporting evidence, that MP may protect against age-related maculopathy (ARM). This study was undertaken to investigate the relationship between dietary intake of L and Z, serum concentrations of these carotenoids, and MP optical density in 828 healthy Irish subjects. METHODS: Dietary intake of L and Z was assessed with a validated food-frequency questionnaire, and serum concentrations of these carotenoids were quantified by high-performance liquid chromatography. MP optical density was measured psychophysically, using heterochromatic flicker photometry. Demographic data, lifestyle data, and general health status, were also recorded by questionnaire, with particular attention directed toward risk-factors (established and putative) for ARM. RESULTS: The relationships between MP optical density, serum concentrations of L (and Z), and dietary intake of L (and Z) were positive and statistically significant when analyzed for the entire study group (r = 0.136-0.303; P 27, did not demonstrate a positive and significant relationship between MP optical density and serum concentrations of Z (r = 0.041, r = 0.001, r = 0.074 and r = 0.082, respectively; P > 0.05 for all). However, there was a positive and significant relationship between MP optical density and serum concentrations of L in the presence of all these risk factors (r = 0.165 to 0.257), except for current heavy smokers (r = 0.042; P > 0.05). CONCLUSIONS: For subjects at increased risk of ARM (e.g., subjects with a clinically confirmed family history of ARM, current heavy cigarette smokers, subjects aged > 53 years and subjects with a BMI > 27) retinal capture and/or retinal stabilization of Z appears to be compromised, whereas retinal uptake and/or stabilization of L appears to be compromised in current heavy smokers only. Given the lack of MP in association with risk for ARM, the findings indicate that a retina predisposed to this condition may have an impaired ability to accumulate circulating Z

Multiwavelength Transit Observations of the Candidate Disintegrating Planetesimals Orbiting WD 1145+017

We present multiwavelength, ground-based follow-up photometry of the white dwarf WD 1145+017, which has recently been suggested to be orbited by up to six or more short-period, low-mass, disintegrating planetesimals. We detect nine significant dips in flux of between 10% and 30% of the stellar flux in our ~32 hr of photometry, suggesting that WD 1145+017 is indeed being orbited by multiple, short-period objects. Through fits to the asymmetric transits that we observe, we confirm that the transit egress is usually longer than the ingress, and that the transit duration is longer than expected for a solid body at these short periods, all suggesting that these objects have cometary tails streaming behind them. The precise orbital periods of the planetesimals are unclear, but at least one object, and likely more, have orbital periods of ~4.5 hr. We are otherwise unable to confirm the specific periods that have been reported, bringing into question the long-term stability of these periods. Our high-precision photometry also displays low-amplitude variations, suggesting that dusty material is consistently passing in front of the white dwarf, either from discarded material from these disintegrating planetesimals or from the detected dusty debris disk. We compare the transit depths in the V- and R-bands of our multiwavelength photometry, and find no significant difference; therefore, for likely compositions, the radius of single-size particles in the cometary tails streaming behind the planetesimals must be ~0.15 μm or larger, or ~0.06 μm or smaller, with 2σ confidence

Suicide risk communication and intervention preferences for veterans and service members

Despite the investment of public resources to fight staggering suicide rates among veterans, we know little about how veterans and service members in crisis communicate suicidal ideations, and what interventions they are willing to receive. We aim to identify communication and suicide intervention preferences of veterans and service members in times of crisis. Descriptive statistics were used to explore veterans communication of suicidal ideations. While 89.9% of participants indicated they were willing to speak to someone when having thoughts of suicide, less than 26% of participants indicated they were willing to bring up their thoughts with a crisis line or veterans organization. Rather, they indicate that family members (62.2%) and military friends (51.1%) would be their primary outreach. Logistic regression was used to determine whether or not preferred interventions varied by participant demographic characteristics. While the majority of participants indicated they were willing to allow intervention (88.6%), no one method was accepted by the majority of the population. The most accepted means of communication was to proactively contact a friend or family member about general life struggles (32.6%) or suicide-specific concerns (27.5%). Many participants were open to receiving resources (42.0%), suicide-specific mental health treatment (36.3%), and some sort of lethal means safety intervention (19.1%–26.4%). The age, marital status, and veterans status of participants significantly impacted what interventions they were willing to allow. We discuss the implications of these findings and the need for evidence-based, multimodal interventions in order to assist veterans in need

Miniature exoplanet radial velocity array I: design, commissioning, and early photometric results

The MINiature Exoplanet Radial Velocity Array (MINERVA) is a US-based observational facility dedicated to the discovery and characterization of exoplanets around a nearby sample of bright stars. MINERVA employs a robotic array of four 0.7 m telescopes outfitted for both high-resolution spec- troscopy and photometry, and is designed for completely autonomous operation. The primary science program is a dedicated radial velocity survey and the secondary science objective is to obtain high precision transit light curves. The modular design of the facility and the flexibility of our hardware allows for both science programs to be pursued simultaneously, while the robotic control software provides a robust and efficient means to carry out nightly observations. In this article, we describe the design of MINERVA including major hardware components, software, and science goals. The telescopes and photometry cameras are characterized at our test facility on the Caltech campus in Pasadena, CA, and their on-sky performance is validated. New observations from our test facility demonstrate sub-mmag photometric precision of one of our radial velocity survey targets, and we present new transit observations and fits of WASP-52b—a known hot-Jupiter with an inflated radius and misaligned orbit. The process of relocating the MINERVA hardware to its final destination at the Fred Lawrence Whipple Observatory in southern Arizona has begun, and science operations are expected to commence within 2015

Coherent radar reflections from an electron-beam induced particle cascade

Experiment T-576 ran at SLAC in 2018, in development of a new radar-based detection scheme for ultra-high energy neutrinos. In this experiment, the electron beam (N∼109e− at ∼10 GeV) was directed into a plastic target to simulate a 1019 eV neutrino-induced shower in ice. This shower was interrogated with radio frequency (RF) radiation, in an attempt to measure a radar-like reflection from the ionization produced in the target during the particle shower. This technique could be employed to detect the rare interactions of ultra-high-energy neutrinos in dense material, such as polar ice sheets, extending the extant energy range of detected neutrinos up to EeV and beyond. In this proceeding, we detail the experiment and present results from the analysis and the observation of a signal consistent with a radar signal