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1.
Clin Teach ; 21(2): e13647, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37665024

ABSTRACT

BACKGROUND: Emotional intelligence (EI) has been previously associated with teaching ability and impostor phenomenon (IP) in medical education; however, studies have demonstrated mixed findings and have largely focused on trainees only. Therefore, we sought to explore the potential association between the degree of IP characteristics, EI and teaching ability in obstetrics and gynaecology (Ob/Gyn) faculty physicians. METHODS: A cross-sectional, survey-based pilot study was completed at a single academic institution. Ob/Gyn attending (faculty) physicians were queried using surveys related to IP, EI and teaching ability. Resident (trainee) physicians also completed anonymous evaluations of faculty teaching ability. FINDINGS: The degree of IP characteristics correlated negatively with self-perceived teaching ability, with no significant differences in resident assessment of faculty teaching. IP also correlated negatively with EI. Although there were no statistically significant differences in resident assessment of teaching ability based on EI, both EI and IP demonstrated inverse relationships to faculty assessment of teaching ability compared with resident assessment. CONCLUSION: IP appears to relate to lower perceived teaching ability in Ob/Gyn faculty that does not correspond to resident evaluation of teaching performance. The demonstrated negative correlation between the degree of impostor characteristics and EI suggests that EI could potentially play a protective role in the development of IP and burnout, as well as influence teaching. This relationship may have implications for faculty willingness to continue in academic medicine.


Subject(s)
Anxiety Disorders , Gynecology , Internship and Residency , Humans , Cross-Sectional Studies , Pilot Projects , Gynecology/education , Emotional Intelligence , Self Concept
3.
J Forensic Leg Med ; 96: 102505, 2023 May.
Article in English | MEDLINE | ID: mdl-37094462

ABSTRACT

PURPOSE: To review aspects of the underlying methodological procedures in Atlas Methods of Dental Age Estimation (DAE) research publications. Attention is paid to issues of Reference Data supporting the Atlases, details of analytic procedures in the development of the Atlases, the statistical reporting of results of Age Estimation (AE), the problems of expressing uncertainty, and the viability of conclusions in the reporting of DAE studies. METHODS: Research reports utilizing Dental Panoramic Tomographs for creating Reference Data Sets (RDS) were studied to unravel the processes of creating Atlases with a view to determining the appropriate procedures for developing numerical RDS and compiling them into an Atlas format to enable DAE of child subjects without birth records. RESULTS: The five different Atlases reviewed gave several different results in terms of AE. The possible causes of this were discussed - namely inadequate representation of Reference Data (RD) and lack of clarity in expressing uncertainty. It is suggested that the method of compiling Atlases needs to be more clearly defined. The yearly intervals described by some of the Atlases fails to take account of the Uncertainty of Estimates which is usually slightly greater than ±2½ years. CONCLUSION: The review of published Atlas design papers in the field of DAE shows a number of different study designs, statistical procedures, and presentational styles, particularly with regard to the statistical procedures and findings. These show that Atlas methods can only be accurate to what amounts to at best a year. RECOMMENDATIONS: Atlas methods lack the accuracy and precision of other methods of AE an example of which is the Simple Average Method (SAM).1 This inherent lack of accuracy must be taken into account when using Atlas methods for AE.


Subject(s)
Logic , Research Design , Child , Humans
4.
Am J Forensic Med Pathol ; 44(1): 33-41, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36165591

ABSTRACT

ABSTRACT: Medicolegal authorities use forensic dental age assessment of children to establish a biologic profile to assist in human identification, answer questions related to immigration, and answer questions used to substantiate eligibility for social benefits. The goal of this study was to assess the performance reliability of the child dental age assessment data previously published for White and Black children in the United States. A total of 432 dental panoramic radiographs were obtained from 3 geographic locations in the United States: Memphis, Tennessee, Knoxville, Tennessee, and Saint Louis, Missouri. Radiographs were staged, and the estimated age was calculated using the previously published data. Multiple age assessments were conducted to determine the effect of excluding certain teeth on estimated age. The results indicated estimated ages using the previously published reference data set were accurate and concordant with known chronologic age across the ancestral, sex, and geographic categories. The results also indicated that the known chronologic age fell within one standard deviation of the estimated age more than the statistical expectation for most categories. Excluding canines provided the most accurate estimation of known chronologic age.


Subject(s)
Age Determination by Teeth , Child , Humans , Age Determination by Teeth/methods , Radiography, Panoramic , Reproducibility of Results , United States , White , Black or African American
5.
JAMA Surg ; 157(9): 835-842, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35921122

ABSTRACT

Importance: Sentinel lymph node (SLN) biopsy is a standard staging procedure for cutaneous melanoma. Regional disease control is a clinically important therapeutic goal of surgical intervention, including nodal surgery. Objective: To determine how frequently SLN biopsy without completion lymph node dissection (CLND) results in long-term regional nodal disease control in patients with SLN metastases. Design, Setting, and Participants: The second Multicenter Selective Lymphadenectomy Trial (MSLT-II), a prospective multicenter randomized clinical trial, randomized participants with SLN metastases to either CLND or nodal observation. The current analysis examines observation patients with regard to regional nodal recurrence. Trial patients were aged 18 to 75 years with melanoma metastatic to SLN(s). Data were collected from December 2004 to April 2019, and data were analyzed from July 2020 to January 2022. Interventions: Nodal observation with ultrasonography rather than CLND. Main Outcomes and Measures: In-basin nodal recurrence. Results: Of 823 included patients, 479 (58.2%) were male, and the mean (SD) age was 52.8 (13.8) years. Among 855 observed basins, at 10 years, 80.2% (actuarial; 95% CI, 77-83) of basins were free of nodal recurrence. By univariable analysis, freedom from regional nodal recurrence was associated with age younger than 50 years (hazard ratio [HR], 0.49; 95% CI, 0.34-0.70; P < .001), nonulcerated melanoma (HR, 0.36; 95% CI, 0.36-0.49; P < .001), thinner primary melanoma (less than 1.5 mm; HR, 0.46; 95% CI, 0.27-0.78; P = .004), axillary basin (HR, 0.61; 95% CI, 0.44-0.86; P = .005), fewer positive SLNs (1 vs 3 or more; HR, 0.32; 95% CI, 0.14-0.75; P = .008), and SLN tumor burden (measured by diameter less than 1 mm [HR, 0.39; 95% CI, 0.26-0.60; P = .001] or less than 5% area [HR, 0.36; 95% CI, 0.24-0.54; P < .001]). By multivariable analysis, younger age (HR, 0.57; 95% CI, 0.39-0.84; P = .004), thinner primary melanoma (HR, 0.40; 95% CI, 0.22-0.70; P = .002), axillary basin (HR, 0.55; 95% CI, 0.31-0.96; P = .03), SLN metastasis diameter less than 1 mm (HR, 0.52; 95% CI, 0.33-0.81; P = .007), and area less than 5% (HR, 0.58; 95% CI, 0.38-0.88; P = .01) were associated with basin control. When looking at the identified risk factors of age (50 years or older), ulceration, Breslow thickness greater than 3.5 mm, nonaxillary basin, and tumor burden of maximum diameter of 1 mm or greater and/or metastasis area of 5% or greater and excluding missing value cases, basin disease-free rates at 5 years were 96% (95% CI, 88-100) for patients with 0 risk factors, 89% (95% CI, 82-96) for 1 risk factor, 86% (95% CI, 80-93) for 2 risk factors, 80% (95% CI, 71-89) for 3 risk factors, 61% (95% CI, 48-74) for 4 risk factors, and 54% (95% CI, 36-72) for 5 or 6 risk factors. Conclusions and Relevance: This randomized clinical trial was the largest prospective evaluation of long-term regional basin control in patients with melanoma who had nodal observation after removal of a positive SLN. SLN biopsy without CLND cleared disease in the affected nodal basin in most patients, even those with multiple risk factors for in-basin recurrence. In addition to its well-validated value in staging, SLN biopsy may also be regarded as therapeutic in some patients. Trial Registration: ClinicalTrials.gov Identifier: NCT00297895.


Subject(s)
Melanoma , Skin Neoplasms , Female , Humans , Lymph Node Excision , Lymphatic Metastasis , Male , Melanoma/pathology , Prognosis , Sentinel Lymph Node Biopsy/methods , Skin Neoplasms/pathology , Skin Neoplasms/surgery
6.
Eval Health Prof ; 45(3): 277-287, 2022 09.
Article in English | MEDLINE | ID: mdl-35191356

ABSTRACT

To construct and validate a scale of emotional intelligence (EI) for the medical field, n = 80 resident physicians responded to a 69-item self-report measure during the pilot phase of development of the Scale of Emotional Functioning: Medicine (SEF:MED). Based on multiple-phase item and structural analyses, a final 36-item version was created based on data from n = 321 respondent residents. Initially exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) supported the expected three-factor solution as did additional CFA from a second sample of n = 113 participants. Internal consistency reliabilities obtained from the original n = 321 residents for the three SEF:MED subscales of Interpersonal Skills (IS), Emotional Awareness (EA), and Emotional Management (EM) were 0.81, 0.82, and 0.84, respectively. Alphas for the second CFA data set were 0.89, 0.87, and 0.88 for IS, EM, and EA, respectively. In addition, the SEF:MED was validated by comparing it to related measures (i.e., the Profile of Emotional Competence (PEC) and the Maslach Burnout Inventory-Human Services Survey for Medical Personnel [MBI-HSS (MP)]); Correlation coefficients between the Total EI composite on the SEF:MED and the PEC global scales ranged from r = 0.64 to 0.68. Finally, correlation coefficients from the Total EI composite on the SEF:MED significantly related to the MBI-HSS (MP) Emotional Exhaustion (EE), Depersonalization (DP), and Personal Accomplishment (PA) scales (r = -0.50, -0.44, and 0.52, respectively). The SEF:MED may provide useful data to physicians and other medical professionals as they consider their own well-being and how it may affect care of their patients.


Subject(s)
Burnout, Professional , Internship and Residency , Physicians , Burnout, Professional/psychology , Emotional Intelligence , Humans , Physicians/psychology , Surveys and Questionnaires
7.
Ann Surg Oncol ; 29(3): 1620-1626, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34853942

ABSTRACT

BACKGROUND: Merkel cell polyomavirus (MCPyV) is associated with the development of Merkel cell carcinoma (MCC). Antibody (MCPyV-Ab) titers may have prognostic implications. This study evaluated the impact of the presence or absence of MCPyV-Ab on the 2-year overall survival (OS) and disease-free survival (DFS) of MCC patients. METHODS: This single-center, IRB-approved, retrospective cohort study evaluated 51 adult patients with MCC from 2014 to 2021 using a prospectively maintained database. Patients were compared by MCPyV-Ab status, and Kaplan-Meier analysis was used to evaluate 2-year OS and DFS. RESULTS: Of the 51 patients, 13 (25.4%) were seropositive, 41 (80.4%) underwent wide excision, 40 (80.0%) received radiotherapy, and 43 (84.3%) received multimodal therapy. The median follow-up period was 15.5 months (range 1-69.5 months). The median 2-year OS of the entire cohort was not reached. The median 2-year OS was not reached for either the seronegative or the seropositive patients. The difference in 2-year OS between the groups was not statistically significant (p = 0.37). Eight patients, all seronegative, were never rendered disease-free and were removed from recurrence analysis. The seropositive patients experienced no recurrences. Of the 30 seronegative patients, 9 (30.0%) experienced recurrence. The median 2-year DFS of the entire cohort was not reached. The median 2-year DFS of the seronegative group was 22.2 months. The 2-year DFS was not reached for the seropositive cohort. Seropositivity conferred a significantly better 2-year DFS than seronegativity (p = 0.04). CONCLUSION: The MCPyV-Ab seropositive patients demonstrated improved 2-year DFS. The seropositive patients showed a strong trend toward improved 2-year OS, although the difference not statistically significant. This study substantiated the value of MCPyV-Ab assessment for MCC.


Subject(s)
Carcinoma, Merkel Cell , Merkel cell polyomavirus , Skin Neoplasms , Carcinoma, Merkel Cell/therapy , Humans , Prognosis , Retrospective Studies , Skin Neoplasms/therapy
8.
J Surg Educ ; 78(6): e100-e111, 2021.
Article in English | MEDLINE | ID: mdl-34750078

ABSTRACT

OBJECTIVE: Emotional intelligence (EI) is associated with job success in multiple fields, in part, because EI may mitigate stress and burnout. Research suggests these relationships may include teaching. Our purpose is to further explore the relationships between EI, burnout, and teaching for faculty surgeons. DESIGN: With IRB approval, surgical faculty were offered the opportunity to complete personal demographics, the Maslach Burnout Inventory, the SETQ-SMART assessment of teaching ability, and the SEF:MED self-assessment of emotional intelligence. Surgical residents rated faculty teaching ability using the SETQ-SMART SETTING: A medium-sized academic medical center in the Southeast approved to graduate 6 residents per year. PARTICIPANTS: ACGME surgical faculty and general surgical residents PGY1 to PGY5 including preliminary residents, were given the opportunity to participate. RESULTS: Faculty self-assessed teaching scores were significantly different from resident scores for nine (60%) faculty; three (33%) overrated their and 6 (67%) under rated their overall teaching ability, relative to resident ratings. The 3 SEF:MED scales correlated low-moderate to strongly with the SETQ-OTS: IS (r = 0.41, p = 0.13), EM (r = 0.67, p < 0.01), and EA (r = 0.43, p = 0.11). Overall, 8(53%) faculty scored moderate to high on at least 1 of the 3 MBI subscales. Overall self-rated faculty teaching scores correlated negatively with higher EE and DP and positively with PA (r = -0.08, -0.21, and 0.52, p = 0.047; respectively). EI negatively correlated with MBI-EE and DP and positively with PA (r = -0.31, -0.18, 0.45, respectively), though due to the small sample none reach statistical significance with alpha set to 0.05. CONCLUSIONS: In this pilot study, EI is positively correlated to surgical faculty members' teaching ability. Burnout was less strongly correlated with resident-assessed faculty teaching scores, but with similar trends. Finally, EI was correlated with MBI EE, DP, and PA as expected given the literature in other fields. Expanded study is warranted.


Subject(s)
Burnout, Professional , Internship and Residency , Burnout, Professional/psychology , Emotional Intelligence , Faculty , Humans , Pilot Projects , Surveys and Questionnaires
9.
Article in English | MEDLINE | ID: mdl-34568719

ABSTRACT

National guidelines recommend sentinel lymph node biopsy (SLNB) be offered to patients with > 10% likelihood of sentinel lymph node (SLN) positivity. On the other hand, guidelines do not recommend SLNB for patients with T1a tumors without high-risk features who have < 5% likelihood of a positive SLN. However, the decision to perform SLNB is less certain for patients with higher-risk T1 melanomas in which a positive node is expected 5%-10% of the time. We hypothesized that integrating clinicopathologic features with the 31-gene expression profile (31-GEP) score using advanced artificial intelligence techniques would provide more precise SLN risk prediction. METHODS: An integrated 31-GEP (i31-GEP) neural network algorithm incorporating clinicopathologic features with the continuous 31-GEP score was developed using a previously reported patient cohort (n = 1,398) and validated using an independent cohort (n = 1,674). RESULTS: Compared with other covariates in the i31-GEP, the continuous 31-GEP score had the largest likelihood ratio (G2 = 91.3, P < .001) for predicting SLN positivity. The i31-GEP demonstrated high concordance between predicted and observed SLN positivity rates (linear regression slope = 0.999). The i31-GEP increased the percentage of patients with T1-T4 tumors predicted to have < 5% SLN-positive likelihood from 8.5% to 27.7% with a negative predictive value of 98%. Importantly, for patients with T1 tumors originally classified with a likelihood of SLN positivity of 5%-10%, the i31-GEP reclassified 63% of cases as having < 5% or > 10% likelihood of positive SLN, for a more precise, personalized, and clinically actionable SLN-positive likelihood estimate. CONCLUSION: These data suggest the i31-GEP could reduce the number of SLNBs performed by identifying patients with likelihood under the 5% threshold for performance of SLNB and improve the yield of positive SLNBs by identifying patients more likely to have a positive SLNB.


Subject(s)
Gene Expression Profiling/standards , Melanoma/diagnosis , Gene Expression Profiling/methods , Gene Expression Profiling/statistics & numerical data , Humans , Lymphatic Metastasis/diagnosis , Lymphatic Metastasis/prevention & control , Melanoma/surgery , Sentinel Lymph Node/pathology , Sentinel Lymph Node/physiopathology , Sentinel Lymph Node Biopsy/methods , Sentinel Lymph Node Biopsy/standards , Sentinel Lymph Node Biopsy/statistics & numerical data
10.
Melanoma Manag ; 7(2): MMT41, 2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32821373

ABSTRACT

AIM: Talimogene laherparepvec (T-VEC) is an intralesional therapy for unresectable, metastatic melanoma. T-VEC real-world use in the context of anti-PD1-based therapy requires further characterization. MATERIALS & METHODS: A retrospective review of T-VEC use from 1 January 2017 and 31 March 2018 for melanoma patients was conducted at seven US institutions. RESULTS: Among 83 patients, three categories of T-VEC and anti-PD-1 therapy were identified: T-VEC used without anti-PD-1 (n = 29, 35%), T-VEC after anti-PD-1-based therapy (n = 22, 27%) and concurrent T-VEC and anti-PD-1-based therapy (n = 32, 39%). 25% of patients discontinued T-VEC therapy due to no remaining injectable lesions, 37% discontinued T-VEC due to progressive disease. Discontinuation of T-VEC did not differ by anti-PD-1-based therapy use or timing. CONCLUSION: In real-world settings, T-VEC may be used concurrently with or after anti-PD-1-based therapy.

11.
Am Surg ; 85(9): 956-960, 2019 Sep 01.
Article in English | MEDLINE | ID: mdl-31638506

ABSTRACT

Postoperative pain managed with opioids has contributed to the opioid crisis through overprescribing practices. We assessed opioid-prescribing habits and their use by patients undergoing surgery for cutaneous malignancies. An Institutional Review Board-approved retrospective analysis was conducted for patients who underwent skin cancer resection between January 2018 and June 2018. Data were collected from the electronic medical record, and opioid-related data were collected from patient interviews and state registries. There were 120 study participants (42 females and 78 males) with a median age of 67 years (range, 21-94 years). All received preincision local anesthetic: 64 had liposomal bupivacaine (LB) (53%) and 56 had non-LB bupivacaine (47%). Most participants (n = 88) used 0 opioids (73%), including 43 LB-anesthetic (67%) and 45 non-LB-anesthetic (80%). No significance was seen between those with a diagnosis of chronic pain, narcotic tolerance, an area of resection, and nodal sampling groups in opioid use. Four patients (3%) requested a refill. Of 105 prescriptions written for opioids, 99 had leftover opioids for an overprescribing rate of 94 per cent. This study suggests pain after skin cancer surgery is manageable with very limited opioid requirements. Our results support prescribing no more than five opioid tablets for postoperative pain control in patients undergoing resection for skin malignancies.


Subject(s)
Ambulatory Surgical Procedures/adverse effects , Analgesics, Opioid/therapeutic use , Inappropriate Prescribing/statistics & numerical data , Pain, Postoperative/drug therapy , Skin Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Anesthetics, Local/administration & dosage , Bupivacaine/administration & dosage , Female , Humans , Liposomes , Male , Middle Aged , Pain Management/methods , Retrospective Studies , Southeastern United States , Young Adult
12.
Am Surg ; 85(9): 1056-1060, 2019 Sep 01.
Article in English | MEDLINE | ID: mdl-31638524

ABSTRACT

Skin substitutes have shown success in complex wound reconstruction. We evaluate the use of a human acellular dermal matrix (ADM) as a viable alternative to autologous skin grafting for defects secondary to skin cancer excision. An institutional review board-approved, retrospective review of ADM-reconstructed defects secondary to skin cancer excision between 2012 and 2018 was conducted. ADM was indicated in patients with preclusive factors for general anesthesia, protracted procedure time, reluctance for additional donor site wound, and personal choice. We reviewed defect characteristics, healing time, postoperative outcomes, and patient demographics. The 228 participants (151 males, 77 females) had a median age of 72 years (range, 29-95 years), with melanoma diagnosed in 113 (49.6%), squamous cell carcinoma in 61 (26.8%), and basal cell carcinoma in 28 (12.2%) patients. The median interval to complete epidermal coverage was 42 days, with graft failure evident in six patients (2.6%). ADM is a viable, low-morbid alternative for reconstruction of defects secondary to skin cancer excision, with no donor site morbidity. With exception to complete healing time, outcomes are similar to those of autologous grafting.


Subject(s)
Acellular Dermis , Skin Neoplasms/surgery , Skin Transplantation , Adult , Age Factors , Aged , Aged, 80 and over , Carcinoma, Basal Cell/surgery , Carcinoma, Squamous Cell/surgery , Female , Graft Survival , Health Care Costs , Humans , Male , Melanoma/surgery , Middle Aged , Retrospective Studies , Time Factors , Transplantation, Autologous , Wound Healing
13.
Astrobiology ; 19(4): 522-546, 2019 04.
Article in English | MEDLINE | ID: mdl-30869535

ABSTRACT

The Mars Curiosity rover carries a diverse instrument payload to characterize habitable environments in the sedimentary layers of Aeolis Mons. One of these instruments is Sample Analysis at Mars (SAM), which contains a mass spectrometer that is capable of detecting organic compounds via pyrolysis gas chromatography mass spectrometry (py-GC-MS). To identify polar organic molecules, the SAM instrument carries the thermochemolysis reagent tetramethylammonium hydroxide (TMAH) in methanol (hereafter referred to as TMAH). TMAH can liberate fatty acids bound in macromolecules or chemically bound monomers associated with mineral phases and make these organics detectable via gas chromatography mass spectrometry (GC-MS) by methylation. Fatty acids, a type of carboxylic acid that contains a carboxyl functional group, are of particular interest given their presence in both biotic and abiotic materials. This work represents the first analyses of a suite of Mars-analog samples using the TMAH experiment under select SAM-like conditions. Samples analyzed include iron oxyhydroxides and iron oxyhydroxysulfates, a mixture of iron oxides/oxyhydroxides and clays, iron sulfide, siliceous sinter, carbonates, and shale. The TMAH experiments produced detectable signals under SAM-like pyrolysis conditions when organics were present either at high concentrations or in geologically modern systems. Although only a few analog samples exhibited a high abundance and variety of fatty acid methyl esters (FAMEs), FAMEs were detected in the majority of analog samples tested. When utilized, the TMAH thermochemolysis experiment on SAM could be an opportunity to detect organic molecules bound in macromolecules on Mars. The detection of a FAME profile is of great astrobiological interest, as it could provide information regarding the source of martian organic material detected by SAM.


Subject(s)
Exobiology , Extraterrestrial Environment , Fatty Acids/analysis , Mars , Minerals/chemistry , Quaternary Ammonium Compounds/chemistry , Spacecraft , Temperature , Carboxylic Acids/chemistry , Clay/chemistry , Esters/analysis , Fatty Acids/chemistry , Gas Chromatography-Mass Spectrometry , Iron/chemistry , Methanol/chemistry , Silicon Dioxide/chemistry , Time Factors
14.
Case Rep Surg ; 2018: 2903801, 2018.
Article in English | MEDLINE | ID: mdl-30174980

ABSTRACT

Radiation exposure for the average coronary stent placement varies based on a number of factors but typically amounts to 6-11 mSv per patient (compared to 3 mSv background). As with all procedures which utilize radiation, there is an inherent risk of genetic mutation and the possible development of malignancy. Here, we present the case of a 75-year-old male who presented with an exophytic mass on his back following prolonged coronary catheterization with a radiation burn seven years prior. Biopsy of the lesion revealed the mass was consistent with an undifferentiated pleomorphic sarcoma emanating from the site of the radiation burn. After staging studies demonstrated no evidence of metastatic disease, radical excision with negative margins was performed. This case demonstrates that despite the rarity of radiation injury, each incidence necessitates strict monitoring of radiation exposure and continual follow-up due to the risk of malignancy.

15.
Sci Rep ; 8(1): 7586, 2018 05 15.
Article in English | MEDLINE | ID: mdl-29765065

ABSTRACT

Past life on Mars will have generated organic remains that may be preserved in present day Mars rocks. The most recent period in the history of Mars that retained widespread surface waters was the late Noachian and early Hesperian and thus possessed the potential to sustain the most evolved and widely distributed martian life. Guidance for investigating late Noachian and early Hesperian rocks is provided by studies of analogous acidic and sulfur-rich environments on Earth. Here we report organic responses for an acid stream containing acidophilic organisms whose post-mortem remains are entombed in iron sulphates and iron oxides. We find that, if life was present in the Hesperian, martian organic records will comprise microbial lipids. Lipids are a potential sizeable reservoir of fossil carbon on Mars, and can be used to distinguish between different domains of life. Concentrations of lipids, and particularly alkanoic or "fatty" acids, are highest in goethite layers that reflect high water-to-rock ratios and thus a greater potential for habitability. Goethite can dehydrate to hematite, which is widespread on Mars. Mars missions should seek to detect fatty acids or their diagenetic products in the oxides and hydroxides of iron associated with sulphur-rich environments.

16.
Am J Forensic Med Pathol ; 39(2): 87-97, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29557817

ABSTRACT

Critics describe forensic dentists' management of bitemark evidence as junk science with poor sensitivity and specificity and state that linkages to a biter are unfounded. Those vocal critics, supported by certain media, characterize odontologists' previous errors as egregious and petition government agencies to render bitemark evidence inadmissible. Odontologists acknowledge that some practitioners have made past mistakes. However, it does not logically follow that the errors of a few identify a systemic failure of bitemark analysis. Scrutiny of the contentious cases shows that most occurred 20 to 40 years ago. Since then, research has been ongoing and more conservative guidelines, standards, and terminology have been adopted so that past errors are no longer reflective of current safeguards. The authors recommend a comprehensive root analysis of problem cases to be used to determine all the factors that contributed to those previous problems. The legal community also shares responsibility for some of the past erroneous convictions. Currently, most proffered bitemark cases referred to odontologists do not reach courts because those forensic dentists dismiss them as unacceptable or insufficient for analysis. Most bitemark evidence cases have been properly managed by odontologists. Bitemark evidence and testimony remain relevant and have made significant contributions in the justice system.


Subject(s)
Bites, Human , Forensic Dentistry/legislation & jurisprudence , Forensic Dentistry/standards , Certification , Expert Testimony/legislation & jurisprudence , Forensic Dentistry/education , Guidelines as Topic , Humans , Professional Competence , Societies, Dental , United States
17.
Astrobiology ; 18(4): 454-464, 2018 04.
Article in English | MEDLINE | ID: mdl-29298093

ABSTRACT

Jarosite on Mars is of significant geological and astrobiological interest, as it forms in acidic aqueous conditions that are potentially habitable for acidophilic organisms. Jarosite can provide environmental context and may host organic matter. The most common extraction technique used to search for organic compounds on the surface of Mars is pyrolysis. However, thermal decomposition of jarosite releases oxygen into pyrolysis ovens, which degrades organic signals. Jarosite has a close association with the iron oxyhydroxide goethite in many depositional/diagenetic environments. Hematite can form by dehydration of goethite or directly from jarosite under certain aqueous conditions. Goethite and hematite are significantly more amenable than jarosite for pyrolysis experiments employed to search for organic matter. Analysis of the mineralogy and organic chemistry of samples from a natural acidic stream revealed a diverse response for organic compounds during pyrolysis of goethite-rich layers but a poor response for jarosite-rich or mixed jarosite-goethite samples. Goethite units that are associated with jarosite, but do not contain jarosite themselves, should be targeted for organic detection pyrolysis experiments on Mars. These findings are extremely timely, as exploration targets for Mars Science Laboratory include Vera Rubin Ridge (formerly known as "Hematite Ridge"), which may have formed from goethite precursors. Key Words: Mars-Pyrolysis-Jarosite-Goethite-Hematite-Biosignatures. Astrobiology 18, 454-464.


Subject(s)
Geologic Sediments/chemistry , Iron/analysis , Mars , Organic Chemicals/analysis , Sulfur/analysis , Extraterrestrial Environment/chemistry , Ferric Compounds/analysis , Gas Chromatography-Mass Spectrometry , Hot Temperature , Iron Compounds/analysis , Minerals/analysis , Sulfates/analysis , X-Ray Diffraction
20.
J Calif Dent Assoc ; 43(6): 315-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26126347

ABSTRACT

Forensic age estimation is a scientific process that estimates an individual's true chronologic age by assessing skeletal and dental development and maturation. Although human growth and maturation is unique to each individual, dental techniques for estimating age are currently considered the best in assessing true chronologic age particularly during the age range when the dentition is undergoing morphologic development. This article reviews the principles, methodology and commonly used techniques in forensic age estimation cases.


Subject(s)
Age Determination by Teeth/methods , Forensic Dentistry/methods , Age Determination by Skeleton , Age Factors , Bone Development/physiology , Humans , Odontogenesis/physiology
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