Nonphotosynthetic Pigments as Potential Biosignatures

Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data.Comment: 21 pages, 12 figures, 5 tables. Full, published articl

Group A Streptococcus Brain Abscess in a Patient on Adalimumab Therapy

Brain abscesses represent a group of dangerous infections typically caused by a number of classic organisms. Group A Streptococcus is a rare cause of brain abscesses and those patients that do have this particular condition will typically have a distal source of infection. We present a case of patient with a biopsy confirmed Group A Streptococcal without a distal source of infection. His only identifiable risk factor was his adalimumab therapy for ankylosing spondylitis. While adalimumab has not been linked to Streptococcal infection in the past, it has been associated with multiple atypical infections and some of the consequences of its mechanism as a tissue necrosis factor alpha inhibitor can theoretically predispose patients to Streptococcal infection when considered in conjunction with known Streptococcal virulence factors. This case raises the question of whether the patient’s adalimumab therapy may have contributed to his unusual presentation of Streptococcal infection and prompts further consideration and study of the risks of adalimumab and other similar immunosuppressant monoclonal antibodies

Management of Asymptomatic Hypertension in the Inpatient Setting.

Hypertension is common in hospitalized patients and is most often asymptomatic. While there are no guidelines for management of such patients, aggressive blood pressure treatment, including the use of intravenous antihypertensives, is often undertaken. While evidence of benefit is lacking, emerging data suggest that treatment of asymptomatic hypertension in the inpatient setting is associated with adverse outcomes, including acute kidney injury and ischemic stroke. In addition, the intensification of a preexisting antihypertensive regimen at hospital discharge significantly increases the risk of readmission without significant improvement in outpatient hypertension control. Such a combination of a common problem with the demonstrable benefit of a less aggressive approach offers considerable opportunity to improve patient care. This review article will discuss the existent literature and a specific case and make suggestions for improvement of practice

Recognizing Guttate Psoriasis and Initiating Appropriate Treatment

Guttate psoriasis is a less common form of psoriasis. It manifests with numerous small, teardrop shaped, scaly plaques on the trunk and extremities. The etiology includes both environmental and genetic factors. It commonly arises 3-4 weeks following a beta hemolytic streptococcal infection. In some cases, it may be misdiagnosed as an allergy to the antibiotics being used to treat the streptococcal infection. The treatment of guttate psoriasis can vary by severity, but the mainstay treatment includes photo therapy and topical steroids. This case report presents the etiology, clinical findings and current treatment options of guttate psoriasis. It also discusses importance of differentiating guttate psoriasis from an antibiotic allergy. The confusion between the two can often delay and make treatment more difficult

Dementia Care: Confronting Myths in Clinical Management

Enormous challenges of this pervasive life-changing condition. Seeking help, often grasping at straws, victims, and their care providers are confronted with misinformation and myths when they search the internet or other sources. When Persons with Dementia (PWD) and their caregivers believe and/or act on false information, proper treatment may be delayed, and ultimately damage can be done. In this paper, we review commonly misunderstood issues encountered in caring for PWD. Our goal is to equip Primary Care Practitioners (PCPs) with accurate information to share with patients and families, to improve the outcomes of PWD to the greatest extent possible. While there are innumerable myths about dementia and its causes and treatments, we are going to focus on the most common false claims or misunderstandings which we hear in our Internal Medicine practice at Marshall Health. We offer suggestions for busy practitioners approaching some of the more common issues with patients and families in a clinic setting

Gospel Choir Spring Concert

Kennesaw State University School of Music presents Gospel Choir Spring Concert.https://digitalcommons.kennesaw.edu/musicprograms/1391/thumbnail.jp

Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle

The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image in the visible (0.4-0.9 micron) planetary systems of nearby stars simultaneously in 16 spectral bands (resolution R~20). For the ~10 most favorable stars, it will have the sensitivity to discover 2 R_E rocky planets within habitable zones and characterize their surfaces or atmospheres through spectrophotometry. Many more massive planets and debris discs will be imaged and characterized for the first time. With a 1.2m visible telescope, the proposed mission achieves its power by exploiting the most efficient and robust coronagraphic and wavefront control techniques. The Phase-Induced Amplitude Apodization (PIAA) coronagraph used by TOPS allows planet detection at 2 lambda/d with nearly 100% throughput and preserves the telescope angular resolution. An efficient focal plane wavefront sensing scheme accurately measures wavefront aberrations which are fed back to the telescope active primary mirror. Fine wavefront control is also performed independently in each of 4 spectral channels, resulting in a system that is robust to wavefront chromaticity.Comment: 12 pages, SPIE conference proceeding, May 2006, Orlando, Florid