Ocular light exposure has important influences on human health and well-being through modulation of circadian rhythms and sleep, as well as neuroendocrine and cognitive functions. Prevailing patterns ...of light exposure do not optimally engage these actions for many individuals, but advances in our understanding of the underpinning mechanisms and emerging lighting technologies now present opportunities to adjust lighting to promote optimal physical and mental health and performance. A newly developed, international standard provides a SI-compliant way of quantifying the influence of light on the intrinsically photosensitive, melanopsin-expressing, retinal neurons that mediate these effects. The present report provides recommendations for lighting, based on an expert scientific consensus and expressed in an easily measured quantity (melanopic equivalent daylight illuminance (melaponic EDI)) defined within this standard. The recommendations are supported by detailed analysis of the sensitivity of human circadian, neuroendocrine, and alerting responses to ocular light and provide a straightforward framework to inform lighting design and practice.
Hemorrhagic shock (HS) and trauma is currently the leading cause of death in young adults worldwide. Morbidity and mortality after HS and trauma is often the result of multi-organ failure such as ...acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), conditions with few therapeutic options. Bone marrow derived mesenchymal stem cells (MSCs) are a multipotent stem cell population that has shown therapeutic promise in numerous pre-clinical and clinical models of disease. In this paper, in vitro studies with pulmonary endothelial cells (PECs) reveal that conditioned media (CM) from MSCs and MSC-PEC co-cultures inhibits PEC permeability by preserving adherens junctions (VE-cadherin and β-catenin). Leukocyte adhesion and adhesion molecule expression (VCAM-1 and ICAM-1) are inhibited in PECs treated with CM from MSC-PEC co-cultures. Further support for the modulatory effects of MSCs on pulmonary endothelial function and inflammation is demonstrated in our in vivo studies on HS in the rat. In a rat "fixed volume" model of mild HS, we show that MSCs administered IV potently inhibit systemic levels of inflammatory cytokines and chemokines in the serum of treated animals. In vivo MSCs also inhibit pulmonary endothelial permeability and lung edema with concurrent preservation of the vascular endothelial barrier proteins: VE-cadherin, Claudin-1, and Occludin-1. Leukocyte infiltrates (CD68 and MPO positive cells) are also decreased in lungs with MSC treatment. Taken together, these data suggest that MSCs, acting directly and through soluble factors, are potent stabilizers of the vascular endothelium and inflammation. These data are the first to demonstrate the therapeutic potential of MSCs in HS and have implications for the potential use of MSCs as a cellular therapy in HS-induced lung injury.
Ten percent of deaths worldwide are due to trauma, and it is the third most common cause of death in the United States. Despite a profound upregulation in procoagulant mechanisms, one-quarter of ...trauma patients present with laboratory-based evidence of trauma-induced coagulopathy (TIC), which is associated with poorer outcomes including increased mortality. The most common causes of death after trauma are hemorrhage and traumatic brain injury (TBI). The management of TIC has significant implications in both because many hemorrhagic deaths could be preventable, and TIC is associated with progression of intracranial injury after TBI. This review covers the most recent evidence and advances in our understanding of TIC, including the role of platelet dysfunction, endothelial activation, and fibrinolysis. Trauma induces a plethora of biochemical and physiologic changes, and despite numerous studies reporting differences in coagulation parameters between trauma patients and uninjured controls, it is unclear whether some of these differences may be “normal” after trauma. Comparisons between trauma patients with differing outcomes and use of animal studies have shed some light on this issue, but much of the data continue to be correlative with causative links lacking. In particular, there are little data linking the laboratory-based abnormalities with true clinically evident coagulopathic bleeding. For these reasons, TIC continues to be a significant diagnostic and therapeutic challenge.
Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ...ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (> 6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.
Hemorrhage remains the leading cause of death in trauma patients. Proximal aortic occlusion, usually performed by direct aortic cross-clamping via thoracotomy, can provide temporary hemodynamic ...stability, permitting definitive injury repair. Resuscitative endovascular balloon occlusion of the aorta (REBOA) uses a minimally invasive, transfemoral balloon catheter, which is rapidly inserted retrograde and inflated for aortic occlusion, and may control inflow and allow time for hemostasis. We compared resuscitative thoracotomy with aortic cross-clamping (RT) with REBOA in trauma patients in profound hemorrhagic shock.
Trauma registry data was used to compare all patients undergoing RT or REBOA during an 18-month period from two Level 1 trauma centers.
There was no difference between RT (n = 72) and REBOA groups (n = 24) in terms of demographics, mechanism of injury, or Injury Severity Scores (ISSs). There was no difference in chest and abdominal Abbreviated Injury Scale (AIS) scores between the groups. However, the RT patients had lower extremity AIS score as compared with REBOA patients (1.5 0-3 vs. 4 3-4, p < 0.001). Of the 72 RT patients, 45 (62.5%) died in the emergency department, 6 (8.3%) died in the operating room, and 14 (19.4%) died in the intensive care unit. Of the 24 REBOA patients, 4 (16.6%) died in the emergency department, 3 (12.5%) died in the operating room, and 8 (33.3%) died in the intensive care unit. In comparing location of death between the RT and REBOA groups, there were a significantly higher number of deaths in the emergency department among the RT patients as compared with the REBOA patients (62.5% vs. 16.7%, p < 0.001). REBOA had fewer early deaths and improved overall survival as compared with RT (37.5% vs. 9.7%, p = 0.003).
REBOA is feasible and controls noncompressible truncal hemorrhage in trauma patients in profound shock. Patients undergoing REBOA have improved overall survival and fewer early deaths as compared with patients undergoing RT.
Therapeutic study, level IV.
This study encompassed fall-related deaths, including those who died prior to medical care, that were admitted to multiple healthcare institutions, regardless of whether they died at home, in ...long-term care, or in hospice. The common element was that all deaths resulted directly or indirectly from injuries sustained during a fall, regardless of the temporal relationship. This comprehensive approach provides an unusual illustration of the clinical sequence of fall-related deaths. Understanding this pathway lays the groundwork for identification of gaps in healthcare needs.
This is a retrospective study of 2014 fall-related deaths recorded by one medical examiner's office (n = 511) within a larger dataset of all trauma related deaths (n = 1848). Decedent demographic characteristics and fall-related variables associated with the deaths were coded and described.
Of those falling, 483 (94.5%) were from heights less than 10 feet and 394 (77.1%) were aged 65+. The largest proportion of deaths (n = 267, 52.3%) occurred post-discharge from an acute care setting. Of those who had a documented prior fall, 216 (42.3%) had a history of one fall while 31 (6.1%) had ≥2 falls prior to their fatal incident. For the 267 post-acute care deaths, 440 healthcare admissions were involved in their care. Of 267 deaths occurring post-acute care, 129 (48.3%) were readmitted within 30 days. Preventability, defined as opportunities for improvement in care that may have influenced the outcome, was assessed. Of the 1848 trauma deaths, 511 (27.7%) were due to falls of which 361 (70.6%) were determined to be preventable or potentially preventable.
Our data show that readmissions and repeated falls are frequent events in the clinical sequence of fall fatalities. Efforts to prevent fall-related readmissions should be a top priority for improving fall outcomes and increasing the quality of life among those at risk of falling.
The purpose of this study was to determine if emergency tourniquet use saved lives.
Tourniquets have been proposed as lifesaving devices in the current war and are now issued to all soldiers. Few ...studies, however, describe their actual use in combat casualties.
A prospective survey of injured who required tourniquets was performed over 7 months in 2006 (NCT00517166 at ClinicalTrials.gov). Follow-up averaged 28 days. The study was at a combat support hospital in Baghdad. Among 2,838 injured and admitted civilian and military casualties with major limb trauma, 232 (8%) had 428 tourniquets applied on 309 injured limbs. We looked at emergency tourniquet use, and casualties were evaluated for shock (weak or absent radial pulse) and prehospital versus emergency department (ED) tourniquet use. We also looked at those casualties indicated for tourniquets but had none used. We assessed survival rates and limb outcome.
There were 31 deaths (13%). Tourniquet use when shock was absent was strongly associated with survival (90% vs. 10%; P < 0.001). Prehospital tourniquets were applied in 194 patients of which 22 died (11% mortality), whereas 38 patients had ED application of which 9 died (24% mortality; P = 0.05). The 5 casualties indicated for tourniquets but had none used had a survival rate of 0% versus 87% for those casualties with tourniquets used (P < 0.001). Four patients (1.7%) sustained transient nerve palsy at the level of the tourniquet. No amputations resulted solely from tourniquet use.
Tourniquet use when shock was absent was strongly associated with saved lives, and prehospital use was also strongly associated with lifesaving. No limbs were lost due to tourniquet use. Education and fielding of prehospital tourniquets in the military environment should continue.
Wireless vehicle-to-vehicle (V2V) and vehicle-toinfrastructure (V2I) communication holds great promise for significantly reducing the human and financial costs of vehicle collisions. A common ...characteristic of this communication is the broadcast of a device's core state information at regular intervals (e.g., vehicle speed and location or traffic signal state and timing). Unless controlled, the aggregate of these broadcasts will congest the channel under dense traffic scenarios, reducing the effectiveness of collision avoidance applications that use transmitted information. Active congestion control using distributed techniques is a topic of great interest for establishing the scalability of this technology. This paper defines a new adaptive congestion control algorithm that can be applied to the message rate of devices in this vehicular environment. While other published approaches rely on binary control, the LInear MEssage Rate Integrated Control (LIMERIC) algorithm takes advantage of full-precision control inputs that are available on the wireless channel. The result is provable convergence to fair and efficient channel utilization in the deterministic environment, under simple criteria for setting adaptive parameters. This "perfect" convergence avoids the limit cycle behavior that is inherent to binary control. We also discuss several practical aspects associated with implementing LIMERIC, including guidelines for the choice of system parameters to obtain desired utilization outcomes, a gain saturation technique that maintains robust convergence under all conditions, convergence with asynchronous updates, and using channel load to determine the aggregate message rate that is observable at a receiver. This paper also extends the convergence analysis for two important cases, i.e., measurement noise in the input signal and delay in the update process. This paper illustrates key analytical results using MATLAB numerical results and employs standard NS-2 simulations to demonstrate the performance of LIMERIC in several high-density scenarios.
To date, no civilian studies have demonstrated that pre-hospital (PH) tourniquets improve survival. We hypothesized that late, trauma center (TC) tourniquet use would increase death from hemorrhagic ...shock compared to early (PH) placement.
All patients arriving to a Level 1, urban TC between October 2008 and January 2016 with a tourniquet placed before (T-PH) or after arrival to the TC (T-TC) were evaluated. Cases were assigned the following designations: indicated (absolute indication vascular injury requiring repair/ligation, operation within 2 hours for extremity injury, or traumatic amputation or relative indication major musculoskeletal/soft tissue injury requiring operation 2-8 hours after arrival, documented large blood loss) or non-indicated. Outcomes were death from hemorrhagic shock, physiology upon arrival to the TC, and massive transfusion requirements. After univariate analysis, logistic regression was carried out to assess independent predictors of death from hemorrhagic shock.
A total of 306 patients received 326 tourniquets for injuries to 157 upper and 147 lower extremities. Two hundred eighty-one (92%) had an indication for placement. Seventy percent of patients had a blunt mechanism of injury. T-TC patients arrived with a lower systolic blood pressure (SBP, 101 86, 123 vs. 125 100, 145 mm Hg, p < 0.001), received more transfusions in the first hour of arrival (55% vs. 34%, p = 0.02), and had a greater mortality from hemorrhagic shock (14% vs. 3.0%, p = 0.01). When controlling for year of admission, mechanism of injury and shock upon arrival (SBP ≤90 mm Hg or HR ≥120 bpm or base deficit ≤ 4) indicated T-TC had a 4.5-fold increased odds of death compared to T-PH (OR 4.5, 95% CI 1.23-16.4, p = 0.02).
Waiting until TC arrival to control hemorrhage with a tourniquet was associated with worsened blood pressure and increased transfusion within the first hour of arrival. In routine civilian trauma patients, delaying to T-TC was associated with 4.5-fold increased odds of mortality from hemorrhagic shock.
Level IV.
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