Evidence from central Mexico supporting the Younger Dryas extraterrestrial impact hypothesis.

We report the discovery in Lake Cuitzeo in central Mexico of a black, carbon-rich, lacustrine layer, containing nanodiamonds, microspherules, and other unusual materials that date to the early Younger Dryas and are interpreted to result from an extraterrestrial impact. These proxies were found in a 27-m-long core as part of an interdisciplinary effort to extract a paleoclimate record back through the previous interglacial. Our attention focused early on an anomalous, 10-cm-thick, carbon-rich layer at a depth of 2.8 m that dates to 12.9 ka and coincides with a suite of anomalous coeval environmental and biotic changes independently recognized in other regional lake sequences. Collectively, these changes have produced the most distinctive boundary layer in the late Quaternary record. This layer contains a diverse, abundant assemblage of impact-related markers, including nanodiamonds, carbon spherules, and magnetic spherules with rapid melting/quenching textures, all reaching synchronous peaks immediately beneath a layer containing the largest peak of charcoal in the core. Analyses by multiple methods demonstrate the presence of three allotropes of nanodiamond: n-diamond, i-carbon, and hexagonal nanodiamond (lonsdaleite), in order of estimated relative abundance. This nanodiamond-rich layer is consistent with the Younger Dryas boundary layer found at numerous sites across North America, Greenland, and Western Europe. We have examined multiple hypotheses to account for these observations and find the evidence cannot be explained by any known terrestrial mechanism. It is, however, consistent with the Younger Dryas boundary impact hypothesis postulating a major extraterrestrial impact involving multiple airburst(s) and and/or ground impact(s) at 12.9 ka.

Patient and caregiver experience following ambulatory surgery: qualitative analysis in a cohort of patients 65 yr and older.

PURPOSE: Patients over the age of 65 represent 15% of Canada's population and one-third of patients undergoing surgery. Older surgical patients often have lasting disability following "minor" ambulatory procedures. This study sought to explore the postoperative experience of ambulatory surgery, as described by older surgical patients and their caregivers. METHODS: Following research ethics board approval, patients 65 yr of age and older who were booked for ambulatory surgical procedures and their caregivers were recruited for the study. Both patients and caregivers were given a daily diary in which to respond to questions assessing functional autonomy, postoperative pain, and caregiver burden. Each daily entry concluded with the following request: "Using the space provided, please record any comments related to your postoperative experience as a patient (caregiver) that you feel are important for us to know." Responses were analyzed for emergent themes using qualitative description. RESULTS: There were 105 patient-caregiver dyads assessed: 90 patients and 64 caregivers offered at least one response. Ten themes, each with a positive and negative construct, clustered around three categories emerged from the comments. Anticipated themes regarding efficacy and side effects of perioperative care were noted. The impact of physical disability on home life was vividly described. Both patients and caregivers expressed concerns regarding preoperative information and postoperative support from the institution. CONCLUSIONS: Patients and caregivers ardently described real challenges during convalescence. Ambulatory care facilities should prepare this specific demographic of patients and caregivers for the post-discharge experience. Paramount for participants was the need for clear communication and a commitment to ongoing support following discharge. The trial on which this analysis was based was registered with Clinical Trials.gov (NCT01382251).

Shock-synthesized hexagonal diamonds in Younger Dryas boundary sediments.

The long-standing controversy regarding the late Pleistocene megafaunal extinctions in North America has been invigorated by a hypothesis implicating a cosmic impact at the Allerød-Younger Dryas boundary or YDB (approximately 12,900 +/- 100 cal BP or 10,900 +/- 100 (14)C years). Abrupt ecosystem disruption caused by this event may have triggered the megafaunal extinctions, along with reductions in other animal populations, including humans. The hypothesis remains controversial due to absence of shocked minerals, tektites, and impact craters. Here, we report the presence of shock-synthesized hexagonal nanodiamonds (lonsdaleite) in YDB sediments dating to approximately 12,950 +/- 50 cal BP at Arlington Canyon, Santa Rosa Island, California. Lonsdaleite is known on Earth only in meteorites and impact craters, and its presence strongly supports a cosmic impact event, further strengthened by its co-occurrence with other nanometer-sized diamond polymorphs (n-diamonds and cubics). These shock-synthesized diamonds are also associated with proxies indicating major biomass burning (charcoal, carbon spherules, and soot). This biomass burning at the Younger Dryas (YD) onset is regional in extent, based on evidence from adjacent Santa Barbara Basin and coeval with broader continent-wide biomass burning. Biomass burning also coincides with abrupt sediment mass wasting and ecological disruption and the last known occurrence of pygmy mammoths (Mammuthus exilis) on the Channel Islands, correlating with broader animal extinctions throughout North America. The only previously known co-occurrence of nanodiamonds, soot, and extinction is the Cretaceous-Tertiary (K/T) impact layer. These data are consistent with abrupt ecosystem change and megafaunal extinction possibly triggered by a cosmic impact over North America at approximately 12,900 +/- 100 cal BP.

SHADES of grey - The challenge of 'grumbling' cauda equina symptoms in older adults with lumbar spinal stenosis.

Diagnosing cauda equina syndrome is challenging in older adults with lumbar spinal stenosis. Understanding these challenges is vital for clinicians who are faced with difficult decisions about when to refer for investigation or surgical management. This is a growing clinical issue because of the escalating prevalence of lumbar spinal stenosis in our ageing population, and increasing demands on healthcare services including imaging and surgical services. This professional issue explores the challenges and evidence gaps relating to cauda equina syndrome in older adults with lumbar spinal stenosis. The degenerative patho-anatomical changes in the lumbar spine that are responsible for lumbar spinal stenosis also have the potential to lead to a gradual compromise of the cauda equina nerve roots. The clinical presentation may be unclear. As a result, there is a risk that slow-onset 'grumbling' cauda equina symptoms may be overlooked or dismissed in older patients with lumbar spinal stenosis. Furthermore, a lack of standardised diagnostic criteria and management pathways add to the challenges for clinicians diagnosing and managing potential cauda equina compromise associated with lumbar spinal stenosis. We recommend careful assessment, appropriate safety netting, and ongoing clinical monitoring and vigilance when assessing and managing this potentially vulnerable patient group.

A service evaluation of patients suspected of Cauda Equina Syndrome referred to accident and emergency departments from a national telephone triage service.

BACKGROUND: The presentation and management of Cauda Equina Syndrome (CES) remains contentious in medical literature, however it is widely agreed that CES requires emergency medical attention. Physiotherapists will often refer suspected cases to A&E departments for emergency medical review in order to safeguard patient safety. OBJECTIVES: To evaluate the management of patients triaged by a national telephone service referred to A&E for suspected CES. METHOD: Known escalations (17 cases) from January 2017 to June 2017 from a national telephone triage service referred to A&E with suspected CES were included. RESULTS: 53% of cases with CES symptoms that conformed to the BASS definition of having a requirement for diagnostic imaging were not investigated by MRI scan. The MRI and non-MRI groups had similar group sizes (8 : 9) and mean ages (42.4 years ± 8SD and 45.7 years ± 12SD). Overall, there were more females (11) compared to males (6) referred to A&E. CONCLUSION: There appears to be significant variability in the management of this cohort of patients once referred to emergency departments. Further guidance is needed as to when watchful waiting is clinically appropriate, and what best practice should be to facilitate safe patient management.

Assessment and management of cauda equina syndrome.

INTRODUCTION: Cauda equina syndrome (CES) is a rare condition that affects the nerves in the spine supplying the bladder, bowel and sexual function. Identification and subsequent urgent action is required to avoid permanent damage to these essential organs. Delays in diagnosis can have devastating and life changing consequences for patients and result in high cost negligence claims. PURPOSE: The purpose of this masterclass is to examine the current evidence and provide an evidence-based, clinically reasoned approach in the safe management of patients presenting with CES. It will include a focus on the importance of communication, documentation and a practical approach to safety netting those at risk. IMPLICATIONS FOR PRACTICE: CES has significant implications for patients and clinicians alike. Timely, effective diagnosis and management of patients with CES results in a better outcome.

Transcription of Biotic Stress Associated Genes in White Clover (Trifolium repens L.) Differs in Response to Cyst and Root-Knot Nematode Infection.

The transcription of four members of the Kunitz proteinase inhibitor (KPI) gene family of white clover (Trifolium repens L.), designated as Tr-KPI1, Tr-KPI2, Tr-KPI4 and Tr-KPI5, was investigated at both local infection (roots) and systemic (leaf tissue) sites in white clover in response to infection with the clover root knot nematode (CRKN) Meloidogyne trifoliophila and the clover cyst nematode (CCN) Heterodera trifolii. Invasion by the CRKN resulted in a significant decrease in transcript abundance of Tr-KPI4 locally at both 4 days post-infection (dpi) and at 8 dpi, and an increase in transcription of Tr-KPI1 systemically at 8 dpi. In contrast, an increase in transcript abundance of all four Tr-KPI genes locally at 4 and 8 dpi, and an increase of Tr-KPI1, Tr-KPI2, and Tr-KPI5 at 8 dpi systemically was observed in response to infection with the CCN. Challenge of a resistant (R) genotype and a susceptible (S) genotype of white clover with the CCN revealed a significant increase in transcript abundance of all four Tr-KPI genes locally in the R genotype, while an increase in abundance of only Tr-KPI1, Tr-KPI2, and Tr-KPI5 was observed in the S genotype, and only at 4 dpi. The transcript abundance of a member of the1-AMINOCYCLOPROPANE-1-CARBOXYLATE (ACC) SYNTHASE gene family from white clover (Tr-ACS1) was significantly down-regulated locally in response to CRKN infection at 4 and 8 dpi and at 4 dpi, systemically, while abundance increased locally and systemically at 8 dpi in response to CCN challenge. Conversely, the abundance of the jasmonic acid (JA) signalling gene, CORONATINE-INSENSITIVE PROTEIN 1 from white clover (Tr-COI1) increased significantly at 8 dpi locally in response to CRKN infection, but decreased at 8 dpi in response to CCN infection. The significance of this differential regulation of transcription is discussed with respect to differences in infection strategy of the two nematode species.

Resistance Reactions to Meloidogyne trifoliophila in Trifolium repens and T. semipilosum.

The predominant root-knot nematode in New Zealand pastures is Meloidogyne trifoliophila, and a recurrent selection program in Trifolium repens has developed resistance to this species. No data are available, however, on the mechanisms of resistance in T. repens or resistant genotypes of T. semipilosum. The development of M. trifoliophila in roots of T. repens and T. semipilosum was examined weekly after a 2-day inoculation with eggs. More second-stage juveniles (J2) were found in two resistant genotypes of T. repens than in two susceptible ones 1 week after inoculation. J2 did not develop further in resistant genotypes, but in susceptible plants development proceeded to the adult stage, visible at 4 weeks after inoculation. The mode of action of resistance to M. trifoliophila in T. repens and in T. semipilosum was compared after a 24-hour inoculation with J2. Numbers of J2 per root tip ranged from 0 to 12 with a median of one for each species. At 24 hours after inoculation (HAI), similar numbers of J2 were seen in the cortex oriented toward the root tip in both resistant and susceptible genotypes of both plant species. At 48 HAI, accumulations of J2 were seen in the meristem in both resistant and susceptible genotypes of both plant species. At 72 HAI, differences in nematode responses were evident between resistant and susceptible genotypes of both plant species; in susceptible roots, J2 heads were embedded in the developing stele. At this time, a browning reaction in resistant genotypes of both plant species indicated a hypersensitive response, and differences in the reaction were recorded between T. repens and T. semipilosum. More study is needed to determine whether the resistance reaction in T. semipilosum is suitable for introgression or insertion into T. repens.

Using consensus methods in developing clinical guidelines for exercise in managing persistent low back pain.

OBJECTIVES: To generate expert consensus evidence for the purpose of developing more complete guidelines for people with persistent low back pain than is possible using current research evidence alone. Gaps in research evidence lead to incomplete practice recommendations unless a scientific process can provide supplementary consensus evidence that is a basis for additional recommendations. DESIGN: A modified Nominal Group Technique (NGT). This followed a systematic review indicating incomplete research evidence. SETTING: UK-wide coordinated by the Chartered Society of Physiotherapy. PARTICIPANTS: Twenty-three individuals selected for their expertise as clinicians, researchers, managers and patients. METHODS: Three stages: a first-round questionnaire of clinical questions unanswered by the systematic review; an electronic conference for outstanding questions unanswered by the first questionnaire; and a second-round questionnaire for these outstanding questions. All three stages were carried out electronically. RESULTS: Of 17 clinical questions unanswered by the systematic review, consensus evidence was generated for 14 questions by the modified NGT and this led to 14 recommendations for practice. Consensus was not reached for the remaining three questions. CONCLUSIONS: The modified NGT was a practical and cost-effective way of generating consensus evidence from a UK-wide group. The consensus evidence was the basis of appropriately graded recommendations for effective care of people with persistent low back pain. Consensus methods have been little used in physiotherapy to date but are likely to be valuable in developing clinically useful, evidence-based tools for future practice.

Perceptions of outpatients regarding the attire of physiotherapists.

PURPOSE: This study investigated perceptions of patients regarding physiotherapists' attire. METHODS: Three hundred patients in three publicly funded outpatient physiotherapy clinics were asked to complete a questionnaire, ranking four photographed modes of attire (lab coat, tailored dress, "scrubs," and jeans) in terms of professionalism, preference, and appropriateness and rating their level of agreement with four statements about physiotherapists' attire. RESULTS: Response rate was 63.7 %. The lab coat was ranked most professional, tailored dress most preferred, and jeans least professional and least preferred. Although jeans were deemed inappropriate (p < 0.001), strong support was shown for wearing jeans on "casual day" (p = 0.001). Age of respondents influenced the perception of the appropriateness of wearing jeans (p = 0.007 for male therapist; p = 0.017 for female therapist); only the cohort <36 years considered jeans appropriate apparel. Overall exposure to physiotherapists (number of lifetime visits) affected patients' perceptions of the importance of attire (p = 0.039) and the appropriateness of wearing jeans (p = 0.018): as number of visits increased, perceived importance decreased and perceived propriety of jeans increased. CONCLUSION: The findings of this study, the first to examine patients' opinions of physiotherapists' attire, suggest that outpatients made clear distinctions between what they perceived as professional and what they preferred, as well as between the appropriateness of physiotherapists' wearing jeans in general and the appropriateness of their doing so on "casual day." Age and exposure to physiotherapists influenced patients' perceptions of attire.