Four Fallacies and an Oversight: Searching for Martian Life.

While it is anticipated that future human missions to Mars will increase the amount of biological and organic contamination that might be distributed on that planet, robotic missions continue to grow in capability and complexity, requiring precautions to be taken now to protect Mars, and particularly areas of Mars that might be Special Regions. Such precautionary cleanliness requirements for spacecraft have evolved over the course of the space age, as we have learned more about planetary environments, and are the subject of regular deliberations and decisions sponsored by the Committee on Space Research (COSPAR). COSPAR's planetary protection policy is maintained as an international consensus standard for spacecraft cleanliness that is recognized by the United Nations Committee on the Peaceful Uses of Outer Space. In response to the paper presented in this issue by Fairén et al. (2017), we examine both their concept of evidence for possible life on Mars and their logic in recommending that spacecraft cleanliness requirements be relaxed to access Special Regions "before it is too late." We find that there are shortcomings in their plans to look for evidence of life on Mars, that they do not support their contention that appropriate levels of spacecraft cleanliness are unaffordable, that there are major risks in assuming martian life could be identified by nucleic acid sequence comparison (especially if those sequences are obtained from a Special Region contaminated with Earth life), and that the authors do not justify their contention that exploration with dirty robots, now, is preferable to the possibility that later contamination will be spread by human exploration. We also note that the potential effects of contaminating resources and environments essential to future human occupants of Mars are both significant and not addressed by Fairén et al. (2017). Key Words: Mars-Special Region-Mission-Life detection-Planetary protection. Astrobiology 17, 971-974.

Paradoxical augmented relapse in alcohol-dependent rats during deep-brain stimulation in the nucleus accumbens.

Case reports indicate that deep-brain stimulation in the nucleus accumbens may be beneficial to alcohol-dependent patients. The lack of clinical trials and our limited knowledge of deep-brain stimulation call for translational experiments to validate these reports. To mimic the human situation, we used a chronic-continuous brain-stimulation paradigm targeting the nucleus accumbens and other brain sites in alcohol-dependent rats. To determine the network effects of deep-brain stimulation in alcohol-dependent rats, we combined electrical stimulation of the nucleus accumbens with functional magnetic resonance imaging (fMRI), and studied neurotransmitter levels in nucleus accumbens-stimulated versus sham-stimulated rats. Surprisingly, we report here that electrical stimulation of the nucleus accumbens led to augmented relapse behavior in alcohol-dependent rats. Our associated fMRI data revealed some activated areas, including the medial prefrontal cortex and caudate putamen. However, when we applied stimulation to these areas, relapse behavior was not affected, confirming that the nucleus accumbens is critical for generating this paradoxical effect. Neurochemical analysis of the major activated brain sites of the network revealed that the effect of stimulation may depend on accumbal dopamine levels. This was supported by the finding that brain-stimulation-treated rats exhibited augmented alcohol-induced dopamine release compared with sham-stimulated animals. Our data suggest that deep-brain stimulation in the nucleus accumbens enhances alcohol-liking probably via augmented dopamine release and can thereby promote relapse.

[The surgically treated gunshot injury. Securing evidence in hospitals without primary participation of police or legal medicine]. / Die operierte Schussverletzung. Schussspurensicherung im klinischen Bereich ohne primäre Beteiligung der Polizei oder der Rechtsmedizin.

Against the background of a problematic reconstruction of a hunting accident, the question arises how such cases can be handled in hospitals and how exhibits can be adequately dealt with. After evaluating a questionnaire on current conditions of securing evidence in cases of surgically treated gunshot wounds from 26 surgical institutions in Mecklenburg-Western Pomerania and in consideration of the certified advanced training in the field of legal medicine, recommendations are given regarding the securing of evidence within the clinical setting without primary involvement of police or legal medicine.

[Effect of systematic information about psychosocial support services during outpatient radiotherapy. A controlled trial]. / Effekte systematischer Informationen über psychosoziale Angebote während der ambulanten Strahlentherapie. Eine kontrollierte Studie.

BACKGROUND: Up to 50 % of all cancer patients require psychosocial support during the course of their disease. However, only a proportion of these patients make use of the existing services. This is partly because patients are unaware that psychosocial support services are available to them. We investigated whether systematically providing printed information concerning psychosocial support can increase the knowledge and usage of these services, as well as health-related self-efficacy. MATERIALS AND METHODS: In a controlled trial, 108 breast cancer patients were assigned alternately to either an intervention- or a control group. At two predefined time points before and during radiotherapy, patients in the intervention group received correspondence informing them about psychosocial services (psycho-oncology, clinical social work and the Cancer Information Service).The control group received no systematic information. Using a standardized questionnaire, all patients were subsequently questioned about their knowledge of psychosocial support services, their perceived self-efficacy and their use of psychosocial support services. RESULTS: We found that systematic provision of information had a positive effect on the knowledge of psychosocial support services (p = 0.042; d = 0.45) and self-efficacy (p = 0.047; d = 0.42). However, no increase in the actual usage of these services was observed (p = 0.661; d = 0.10). CONCLUSION: The systematic provision of information in the form of written correspondence can easily be implemented into clinical routine and is an effective way to increase cancer patients' knowledge of psychosocial support services. Furthermore, providing information about the services had a positive impact on patients' perceived self-efficacy. However, simply making this information available did not increase the usage of psychosocial support services.

Ethical considerations for planetary protection in space exploration: a workshop.

With the recognition of an increasing potential for discovery of extraterrestrial life, a diverse set of researchers have noted a need to examine the foundational ethical principles that should frame our collective space activities as we explore outer space. A COSPAR Workshop on Ethical Considerations for Planetary Protection in Space Exploration was convened at Princeton University on June 8-10, 2010, to examine whether planetary protection measures and practices should be extended to protect planetary environments within an ethical framework that goes beyond "science protection" per se. The workshop had been in development prior to a 2006 NRC report on preventing the forward contamination of Mars, although it responded directly to one of the recommendations of that report and to several peer-reviewed papers as well. The workshop focused on the implications and responsibilities engendered when exploring outer space while avoiding harmful impacts on planetary bodies. Over 3 days, workshop participants developed a set of recommendations addressing the need for a revised policy framework to address "harmful contamination" beyond biological contamination, noting that it is important to maintain the current COSPAR planetary protection policy for scientific exploration and activities. The attendees agreed that there is need for further study of the ethical considerations used on Earth and the examination of management options and governmental mechanisms useful for establishing an environmental stewardship framework that incorporates both scientific input and enforcement. Scientists need to undertake public dialogue to communicate widely about these future policy deliberations and to ensure public involvement in decision making. A number of incremental steps have been taken since the workshop to implement some of these recommendations.

Robust and efficient walking with spring-like legs.

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Upright human gait did not provide a major mechanical challenge for our ancestors.

Habitual bipedalism is considered as a major breakthrough in human evolution and is the defining feature of hominins. Upright posture is presumably less stable than quadrupedal posture, but when using external support, for example, toddlers assisted by their parents, postural stability becomes less critical. In this study, we show that humans seem to mimic such external support by creating a virtual pivot point (VPP) above their centre of mass. A highly reduced conceptual walking model based on this assumption reveals that such virtual support is sufficient for achieving and maintaining postural stability. The VPP is experimentally observed in walking humans and dogs and in running chickens, suggesting that it might be a convenient emergent behaviour of gait mechanics and not an intentional locomotion behaviour. Hence, it is likely that even the first hominis may have already applied the VPP, a mechanism that would have facilitated the development of habitual bipedalism.

Swing leg control in human running.

Humans can run within a wide range of speeds without thinking about stabilizing strategies. The leg properties seem to be adjusted automatically without need for sensory feedback. In this work, the dynamics of human running are represented by the planar spring mass model. Within this framework, for higher speeds, running patterns can be stable without control strategies. Here, potential strategies that provide stability over a broader range of running patterns are considered and these theoretical predictions are compared to human running data. Periodic running solutions are identified and analyzed with respect to their stability. The control strategies are assumed as linear adaptations of the leg parameters-leg angle, leg stiffness and leg length-during the swing phase. To evaluate the applied control strategies regarding their influence on landing behavior, two parameters are introduced: the velocity of the foot relative to the ground (ground speed matching) and the foot's angle of approach. The results show that periodic running solutions can be stabilized and that control strategies, which guarantee running stability, are redundant. For any swing leg kinematics (adaptation of the leg angle and the leg length), running stability can be achieved by adapting the leg stiffness in anticipation of the ground contact.

[Arrosion bleeding of the brachiocephalic trunc - a late complication after percutaneous dilatative tracheostomy in a patient with a cervical rib abnormality]. / Letale Blutung aus dem Truncus brachiocephalicus - Spätkomplikation nach Fehleinschätzung eines Dilatationstracheostomas bei rudimentärer Halsrippe.

BACKGROUND: In the last years percutaneous dilatative tracheostomy was increasingly established in many intensive care units, mostly performed by the anesthesiologists. This method becomes problematic, when it is used in patients requiring long time intubation. It must always be kept in mind that in the course of further rehabilitation the patients may be treated by persons, who are not familiar with the altered anatomy of the upper airways. This bears the risk for severy complications, like bleeding from major vessels. CASE REPORT: Letal arrosion bleeding of the brachiocephalic trunc was observed in a patient, 3 weeks after percutaneous dilatative tracheostomy (technique by Griggs). As an abnormality the patient had a cervical rib. The wrong position of the tracheostomy tube was not noticed because the patient had no dyspnoea, spontaneously breathing through the nose and mouth instead of through the tracheostomy tube. CONCLUSIONS: Particularly in patients requiring long-time intubation it is essential that the tube can be changed safely. We advocate an "epithelialized" tracheostoma with tracheocutaneous anastomosis for these patients. If the position of the tracheostomy tube is not clear, endoscopic control has to be performed.

The astrobiology primer: an outline of general knowledge--version 1, 2006.

The Astrobiology Primer has been created as a reference tool for those who are interested in the interdisciplinary field of astrobiology. The field incorporates many diverse research endeavors, but it is our hope that this slim volume will present the reader with all he or she needs to know to become involved and to understand, at least at a fundamental level, the state of the art. Each section includes a brief overview of a topic and a short list of readable and important literature for those interested in deeper knowledge. Because of the great diversity of material, each section was written by a different author with a different expertise. Contributors, authors, and editors are listed at the beginning, along with a list of those chapters and sections for which they were responsible. We are deeply indebted to the NASA Astrobiology Institute (NAI), in particular to Estelle Dodson, David Morrison, Ed Goolish, Krisstina Wilmoth, and Rose Grymes for their continued enthusiasm and support. The Primer came about in large part because of NAI support for graduate student research, collaboration, and inclusion as well as direct funding. We have entitled the Primer version 1 in hope that it will be only the first in a series, whose future volumes will be produced every 3-5 years. This way we can insure that the Primer keeps up with the current state of research. We hope that it will be a great resource for anyone trying to stay abreast of an ever-changing field.

Planetary exploration in the time of astrobiology: protecting against biological contamination.

These are intriguing times in the exploration of other solar-system bodies. Continuing discoveries about life on Earth and the return of data suggesting the presence of liquid water environments on or under the surfaces of other planets and moons have combined to suggest the significant possibility that extraterrestrial life may exist in this solar system. Similarly, not since the Viking missions of the mid-1970s has there been as great an appreciation for the potential for Earth life to contaminate other worlds. Current plans for the exploration of the solar system include constraints intended to prevent biological contamination from being spread by solar-system exploration missions.

[Unnatural causes of death--what the pathologist must know]. / Nichtnatürliche Todesfälle--Was der Pathologe wissen muss.

The lecture explains the current legal position in Germany and is intended to help pathologists make decisions. I. The term "unnatural death" is a technical term within the meaning of section 159 German Code of Criminal Procedure. Even "indications"--again a legal term--constitute a statutory duty to make an immediate report. If such causes for suspicion arise at autopsy, the pathologist is confronted with an ethical and legal dilemma. With his report he can trigger a chain of events that is no longer under his control, and may extend well beyond the original request for a medical diagnosis. II. Starting with the relevant definitions for the subject, the lecturer focuses on the special case of unexpected death in connection with medical intervention. Where does the pathologist's responsibility end? Which information channels must be observed? The pathologist's rights, duties and degree of discretion are discussed. III. Finally, the lecturer addresses the "matter of the body" which must be examined by the responsible state prosecutor as a consequence of the pathologist's report.

Implementing planetary protection requirements for sample return missions.

NASA is committed to exploring space while avoiding the biological contamination of other solar system bodies and protecting the Earth against potential harm from materials returned from space. NASA's planetary protection program evaluates missions (with external advice from the US National Research Council and others) and imposes particular constraints on individual missions to achieve these objectives. In 1997 the National Research Council's Space Studies Board published the report, Mars Sample Return: Issues and Recommendations, which reported advice to NASA on Mars sample return missions, complementing their 1992 report, The Biological Contamination of Mars Issues and Recommendations. Meanwhile, NASA has requested a new Space Studies Board study to address sample returns from bodies other than Mars. This study recognizes the variety of worlds that have been opened up to NASA and its partners by small, relatively inexpensive, missions of the Discovery class, as well as the reshaping of our ideas about life in the solar system that have been occasioned by the Galileo spacecraft's discovery that an ocean under the ice on Jupiter's moon Europa might, indeed, exist. This paper will report on NASA's planned implementation of planetary protection provisions based on these recent National Research Council recommendations, and will suggest measures for incorporation in the planetary protection policy of COSPAR.

A consensus approach to planetary protection requirements: recommendations for Mars lander missions.

Over the last several years, the nature of the surface conditions on the planet Mars, our knowledge of the growth capabilities of Earth organisms under extreme conditions, and future opportunities for Mars exploration have been under extensive review in the United States and elsewhere. As part of these examinations, in 1992 the US Space Studies Board made a series of recommendations to NASA on the requirements that should be implemented on future missions that will explore Mars. In particular, significant changes were recommended in the requirements for Mars landers, changes that significantly alleviated the burden of planetary protection implementation for these missions. In this paper we propose a resolution implementing this new set of recommendations, for adoption by COSPAR at its 30th meeting in Hamburg. We also discuss future directions and study areas for planetary protection, in light of changing plans for Mars exploration.

Long-term effects of microgravity and possible countermeasures.

It is well known that long-term exposure to microgravity causes a number of physiological and biochemical changes in humans; among the most significant are: 1) negative calcium balance resulting in the loss of bone; 2) atrophy of antigravity muscles; 3) fluid shifts and decreased plasma volume; and 4) cardiovascular deconditioning that leads to orthostatic intolerance. It is estimated that a mission to Mars may require up to 300 days in a microgravity environment; in the case of an aborted mission, the astronauts may have to remain in reduced gravity for up to three years. Although the Soviet Union has shown that exercise countermeasures appear to be adequate for exposures of up to one year in space, it is questionable whether astronauts could or should have to maintain such regimes for extremely prolonged missions. Therefore, the NASA Life Sciences Division has initiated a program designed to evaluate a number of methods for providing an artificial gravity environment.

Development of countermeasures for medical problems encountered in space flight.

By the turn of this century, long-duration space missions, either in low Earth orbit or for got early planetary missions, will become commonplace. From the physiological standpoint, exposure to the weightless environment results in changes in body function, some of which are adaptive in nature and some of which can be life threatening. Important issues such as environmental health, radiation protection, physical deconditioning, and bone and muscle loss are of concern to life scientists and mission designers. Physical conditioning techniques such as exercise are not sufficient to protect future space travellers. A review of past experience with piloted missions has shown that gradual breakdown in bone and muscle tissue, together with fluid losses, despite a vigorous exercise regimen can ultimately lead to increased evidence of renal stones, musculoskeletal injuries, and bone fractures. Biological effects of radiation can, over long periods of time increase the risk of cancer development. Today, a vigorous program of study on the means to provide a complex exercise regimen to the antigravity muscles and skeleton is under study. Additional evaluation of artificial gravity as a mechanism to counteract bone and muscle deconditioning and cardiovascular asthenia is under study. New radiation methods are being developed. This paper will deal with the results of these studies.

Development of life support requirements for long-term space flight.

When humans move out into the solar system to stay for long durations, the most immediate challenge will be the provision of a life-supporting environment in locations that are naturally devoid of food, air, and water. Life support systems must provide these commodities in all phases of space flight--during intravehicular activity (IVA) and during extra-vehicle activity (EVA). Systems that support human life must provide: overall reliability in the space environment, allowing maintenance and component replacement in space; reduced resupply mass of consumables and spares; for planetary surfaces, the ability to utilize local resources for increased self sufficiency; and the minimized mass power and volume requirements necessary for all space flight systems. This paper will discuss the melding of these technical requirements in such a way as to meet the human needs of space flight.