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Urban populations and the sprawl of urban environments are increasing in the United States as well as globally. The local hydrologic cycle is directly impacted by urban development through greater generation of surface runoff and export of water through subterranean pipes networks to surface water bodies. These pipe networks carry waters that have potentially dramatic effects on the chemistry of groundwater and surface water bodies. In this work, we sampled waters from the Olentangy River and two subterranean outfalls that flow into the river in Columbus, Ohio United States. We measured the major ion, nutrient, and dissolved silica concentrations of each water source to identify how the urban landscape impacts the chemistry of a river that travels from an agricultural landscape to an urban environment. The outfalls had elevated concentrations of all major ions (Na+, K+, Mg2+, Ca2+, Cl−, SO42-) and H4SiO4. However, the Olentangy river typically had greater NO3− and soluble reactive phosphorus (SRP) concentrations. Sources of elevated ion export include road salts and combined storm runoff (Na+, Cl−), municipal water treatment practices (K+, Na+, SO42-), and concrete pipe weathering (Ca2+, Mg2+, K+, H4SiO4, SO42-). Utilizing stable isotopes of water, δ18O and δ2H, we identified that the water in the pipe networks is typically a mix of multiple precipitation events, but there is evidence of flushing following high-volume precipitation events. The contribution of high TDS waters from subterranean urban outfalls modified the ion abundance in the Olentangy river and produces a tendency towards freshwater salinization syndrome. This is particularly apparent when comparing the chemistry of the urban Olentangy to the agricultural corridor of the river and its other source waters. This research details the transformation of a river as it flows from an agricultural to urban landscape and provides data on the chemistry of source waters that facilitate the river’s chemical changes.

Category: Hindfoot; Other Introduction/Purpose: Triple arthrodesis of the subtalar, talonavicular, and calcaneocuboid joints is a commonly performed procedure to treat hindfoot deformity. Debate exists regarding the need to include the calcaneocuboid joint in the arthrodesis, leading some surgeons to perform double arthrodesis of the subtalar and talonavicular joints to treat similar pathology. Differences in clinical, radiographic and patient reported outcomes between the two procedures have not been thoroughly reported. The purpose of this study is to evaluate the clinical and radiographic outcomes of double versus triple arthrodesis for the correction of symptomatic hindfoot deformity. Methods: A retrospective cohort study reviewed all patients who underwent double or triple arthrodesis to correct hindfoot pathology between January 2016 and April 2019 at our institution. Patients were identified using CPT codes. Inclusion criteria included patients greater than 18 years old who underwent hindfoot correction by a primary double or triple arthrodesis with a minimum 3 month clinical and radiographic follow up. Exclusion criteria included prior hindfoot arthrodesis and peripheral neuropathy. The primary outcome was union at each arthrodesis site. Secondary outcomes included deformity correction, operative times, re-operation rates, complications, and patient reported outcomes. Chi-squared or Fisher’s Exact tests were used as appropriate to compare categorical variables and t-tests were used to compare numerical variables. Results: One hundred fourteen procedures met inclusion criteria. There were 86 double (75%) and 28 triple arthrodeses (25%). Eleven talonavicular non-unions were identified in the double arthrodesis group (12.7%) compared to 5 in the triple arthrodesis group (17.9%, p =0.54). There were 2 (7.1%) calcaneocuboid non-unions in the triple group. Subtalar arthrodesis was achieved 100% in both groups. Operative time was shorter for doubles compared to triples, but this did not reach statistical significance (104 min vs 117 min, p = 0.089). The only deformity correction parameter to reach significance was post operative cuboid height being higher in the double group (19.1mm vs 16.7mm, p = 0.012). Pre-operative deformity, overall union rates, reoperation rate, and post operative complications were not statistically different between the two procedures. Conclusion: In this study double arthrodesis was shown to result in shorter operative times with similar deformity correction, union rates, and post operative complications when compared to triple arthrodesis. The double arthrodesis is a viable alternative to treat hindfoot pathology. More research is warranted to further compare the long term outcomes between the two procedures.

The ability to rapidly detect and respond to wildlife morbidity and mortality events is critical for reducing threats to wildlife populations. Surveillance systems that use pre-diagnostic clinical data can contribute to the early detection of wildlife morbidities caused by a multitude of threats, including disease and anthropogenic disturbances. Here, we demonstrate proof of concept for use of a wildlife disease surveillance system, the 'Wildlife Morbidity and Mortality Event Alert System', that integrates pre-diagnostic clinical data in near real-time from a network of wildlife rehabilitation organizations, for early and enhanced detection of unusual wildlife morbidity and mortality events. The system classifies clinical pre-diagnostic data into relevant clinical classifications based on a natural language processing algorithm, generating alerts when more than the expected number of cases is recorded across the rehabilitation network. We demonstrated the effectiveness and efficiency of the system in alerting to events associated with both common and emerging diseases. Tapping into this readily available unconventional general surveillance data stream offers added value to existing wildlife disease surveillance programmes through a relatively efficient, low-cost strategy for the early detection of threats.

Facultative heterochromatin controls development and differentiation in many eukaryotes. In metazoans, plants, and many filamentous fungi, facultative heterochromatin is characterized by transcriptional repression and enrichment with nucleosomes that are trimethylated at histone H3 lysine 27 (H3K27me3). While loss of H3K27me3 results in derepression of transcriptional gene silencing in many species, additional up- and downstream layers of regulation are necessary to mediate control of transcription in chromosome regions enriched with H3K27me3. Here, we investigated the effects of one histone mark on histone H4, namely H4K20me3, in the fungus Zymoseptoria tritici, a globally important pathogen of wheat. Deletion of kmt5, the gene encoding the sole methyltransferase responsible for H4K20 methylation, resulted in global derepression of transcription, especially in regions of facultative heterochromatin. Derepression in the absence of H4K20me3 not only affected known genes but also a large number of novel, previously undetected transcripts generated from regions of facultative heterochromatin on accessory chromosomes. Transcriptional activation in kmt5 deletion strains was accompanied by a complete loss of Ash1-mediated H3K36me3 and chromatin reorganization affecting H3K27me3 and H3K4me2 distribution in regions of facultative heterochromatin. Strains with H4K20L, M or Q mutations in the single histone H4 gene of Z. tritici recapitulated these chromatin changes, suggesting that H4K20me3 is important for Ash1-mediated H3K36me3. The ∆kmt5 mutants we obtained were more sensitive to genotoxic stressors than wild type and both, ∆kmt5 and ∆ash1, showed greatly increased rates of accessory chromosome loss. Taken together, our results provide insights into an unsuspected mechanism involved in the assembly and maintenance of facultative heterochromatin.

The coastal regions of the McMurdo Dry Valleys, Antarctica, contain deposits of the Ross Sea Drift, sedimentary material left from the Ross Sea ice sheet from the advance of the West Antarctic ice sheet during the Last Glacial Maximum. Much of this deposit is ice-cored, but data on the stable isotopic composition of water from this ice, which may contain a valuable climate archive, are sparse or incomplete. Widespread thermokarstic ground subsidence in this “coastal thaw zone” of the McMurdo Dry Valleys suggests that these potential records are rapidly being lost due to the melting of ground ice and permafrost. We collected samples of massive buried ice from the Ross Sea Drift in eastern Taylor Valley for δ18O-H2O and δ2H-H2O and measured a broad range of values (δ18O = −27.7 to −37.3 ‰; δ2H = −210 to −295 ‰). These buried ice deposits do not show evidence of alteration through sublimation or evaporation, plot along the local meteoric water line, and have values that indicate ice deposition under a colder climate than present conditions. We propose that this ice was sourced from the Ross Sea ice sheet during the Last Glacial Maximum and contains a valuable and accessible climate record.

Category: Trauma; Midfoot/Forefoot Introduction/ Purpose: Primary arthrodesis of Lisfranc and midfoot fracture-dislocations is a reliable treatment option, yet concerns remain about nonunion and dorsiflexion malunion. The use of a new generation of nitinol staples has proliferated in midfoot arthrodesis. The purpose of this study is to examine the use of nitinol staples in primary arthrodesis of acute Lisfranc fracture-dislocations, comparing outcomes to traditional plate and screw fixation. The primary hypothesis is that nonunion rates are lower with constructs that include nitinol staples than those with plates and screws alone. Secondary hypotheses are: 1. Total operative and tourniquet time are shorter using nitinol staples. 2. Reoperation rates are lower using nitinol staples. 3. Dorsiflexion malunion rates are lower using nitinol staples. 4. Functional outcome scores will indicate comparable post-arthrodesis disability. Methods: Midfoot fracture-dislocations treated with primary arthrodesis by seven foot and ankle orthopaedic surgeons at a tertiary referral center from 1/1/2012 to 8/1/2021 were reviewed. Patients with open fractures, fractures managed with external fixation, Charcot arthropathy, neuropathy, previous midfoot surgery, or concomitant hindfoot/ankle fractures were excluded. Of 160 eligible patients, 121 patients met the required 4-month minimum radiographic follow-up. Preoperative records were reviewed, evaluating for associated metatarsal and cuneiform fractures, operative and tourniquet time, joints included, and fixation construct. Outcomes were analyzed at both patient and individual joint levels. Patients (121 total) and individual joints (305 total) were categorized as either staples alone (45 patients, 154 joints), staples plus plates and screws (hybrid) (45 patients, 40 joints), or plates and screws alone (31 patients, 111 joints). Postoperative radiographs were analyzed for union and malunion at each joint fused. Medical records were reviewed for postoperative complications. FAAM, VR-12, and NPRS were collected. Results: When assessed at the individual joint level, the nonunion rate was higher (8.1%, 9/111) among joints fixed with plate and screw constructs than with hybrid (2.5%, 1/40) or staple only constructs (1.3%, 2/154) (P = 0.017). Of the 12 nonunions in the study, 6 had either a metatarsal or cuneiform fracture. Median OR and tourniquet time were both shorter for hybrid (92 & 83 minutes) and staple only (67 & 63 minutes) constructs compared to plate and screw only fixation (106 & 95 minutes) (P = 0.0003 & < 0.0001). There were 15 (12.4%) reoperations including 10 hardware removals, 3 nonunion revisions, and 1 malunion revision. There was no difference in reoperation, malunion (14 total, 11.6%), or patient reported outcome measure between fixation types. Conclusion: Nitinol staples are effective in achieving bony fusion when used alone or in combination with plates and screws. Their use should be considered for primary arthrodesis of Lisfranc and midfoot fracture-dislocations due to lower rates of nonunion and shorter tourniquet and operative time compared to traditional plate and screw fixation. Further studies are needed to determine if staples decrease the risk for dorsiflexion malunion and improve patient reported outcomes.

Category: Ankle Arthritis; Ankle Introduction/Purpose: The two most common surgical procedures for end stage ankle arthritis patients who fail conservative management are arthrodesis and arthroplasty. The appropriateness of total ankle arthroplasty versus arthrodesis remains controversial. The long-term outcomes of current generation prostheses are not yet available and there is continued debate regarding the cost-benefit and risk-benefit analysis of each procedure. This study seeks to document rates of arthroplasty and arthrodesis for ankle osteoarthritis in New York in order to ascertain utilization of each procedure over time and stratification by patient demographics. Methods: Patients from 2009-2018 were identified using International Classification of Disease (ICD)-9 and 10 Clinical Modification (CM) codes for ankle osteoarthritis and Current Procedural Terminology or ICD-9 CM and ICD-10 Procedural Classification System procedural codes for ankle arthrodesis or ankle arthroplasty in the New York Statewide Planning and Research Cooperative System (SPARCS) database. SPARCS is an all-payer database collecting outpatient (emergency department, ambulatory surgery, and hospital-based clinic visits) and all inpatient claims in New York. A trend analysis was performed to determine if there was a shift towards either ankle arthrodesis or ankle arthroplasty over time. A multivariable logistic regression was performed to assess the impact of patient demographic factors on the likelihood of receiving arthrodesis versus arthroplasty. The variables included in the analysis were age, sex, race, ethnicity, Social Deprivation Index (linked by ZIP code), Charlson Comorbidity Index, and primary insurance type. Results: 3,735 cases were included in the trend analysis in years 2009-2018. In 2009, 220 (84%) procedures were ankle arthrodesis and 42 (16%) were ankle arthroplasty. By 2018, 274 (43.2%) were ankle arthrodesis and 360 (56.8%) were ankle arthroplasty (p=1 Charlson comorbidities (OR: 1.4, p=.0007) was associated with increased odds of arthrodesis compared to arthroplasty. Conclusion: The present study demonstrates a substantial rise in ankle arthroplasty volume without a matching decrease in ankle arthrodesis volume over ten years. Patients who are wary of the motion limitation of arthrodesis and would previously have gravitated towards nonoperative management may now be finding a commonly performed, motion sparing alternative in arthroplasty. Ankle arthrodesis volume slightly increased, suggestive of nonequivalent patient populations undergoing these two procedures. There are apparent socioeconomic disparities in the utilization of these procedures, likely stemming from numerous nuanced factors but nevertheless also likely reflective of disparities in foot and ankle healthcare access.

Background: Ankle arthroplasty has emerged as a viable alternative to ankle arthrodesis due in large part to recent advancements in both surgical technique and implant design. This study seeks to document trends of arthroplasty and arthrodesis for ankle osteoarthritis in New York State from 2009-2018 in order to determine if patient demographics play a role in procedure selection and to ascertain the utilization of each procedure and rates of complications. Methods: Patients 40 years and older from 2009-2018 were identified using International Classification of Diseases, Ninth and Tenth Revisions ( ICD-9 and ICD-10 ), Clinical Modification ( CM ) diagnosis and procedure codes for ankle osteoarthritis, ankle arthrodesis, and ankle arthroplasty in the New York statewide planning and research cooperative system database. A trend analysis for both inpatient and outpatient procedures was performed to evaluate the changing trends in utilization of ankle arthrodesis and ankle arthroplasty over time. A multivariable logistic regression was used to assess the odds of receiving ankle arthrodesis relative to ankle arthroplasty. Complications were compared between inpatient ankle arthrodesis and arthroplasty using multivariable Cox proportional hazards regression. Results: A total of 3735 cases were included. Ankle arthrodesis increased by 25%, whereas arthroplasty increased by 757%. African American race, federal insurance, workers compensation, presence of comorbidities, and higher social deprivation were associated with increased odds of having an ankle arthrodesis vs an ankle arthroplasty. Compared with ankle arthroplasty, ankle arthrodesis was associated with increased rates of readmission, surgical site infection, acute renal failure, cellulitis, urinary tract infection, and deep vein thrombosis. Conclusion: Ankle arthroplasty volume has grown substantially without a decrease in ankle arthrodesis volume, suggesting that ankle arthroplasty may be selectively used for a different population of patients than ankle arthrodesis patients. Despite the increased growth of ankle arthroplasty, certain patient demographics including patients from minority populations, federal insurance, and from areas of high social deprivation have higher odds of receiving arthrodesis. Level of Evidence: Level III, retrospective cohort.

Three dimensional printing is an additive manufacturing process by which a 3D structure is created from a digital blueprint. It is a technology that is increasingly utilized by surgeons as a resource for preoperative planning and intraoperative guidance. In the field of orthopedic surgery, 3D printed models have not been thoroughly evaluated as an educational resource. The current study aims, first, to evaluate 3D models of pilon fractures for their fidelity compared to the corresponding CT blueprints and, second, to evaluate 3D printed models as teaching tools. Pilon fractures of the distal tibial articular surface are complex in nature and a good representation of high-­‐energy injury. They pose challenges to both learning with traditional two-­‐dimensional or virtual three-­‐dimensional resources and to adequate understanding of fracture anatomy. It is hypothesized that 3D printed models will be accurate compared to corresponding clinical CT datasets. This study showed through distances between landmarks and by surface characteristic analysis that micro-­‐ CTs of 3D printed models are accurate compared to the corresponding clinical CTs, but that variation is introduced when converting clinical CTs to 3D printed models to micro-­‐CTs.

Study region: Ireland Study focus: Multiple studies have established that catchment geology and weathering regime strongly influence surface water chemistry, and that geochemical cycling can vary due to seasonal climatic conditions. However, fewer studies have focused on the influence these controls in a holistic manner. We relate the water chemistry of a country-wide Irish river survey to atmospheric input, underlying geology, and the influence of bogs. Climatic conditions were defined by an atypically wet winter and an unusually dry summer, providing the opportunity to investigate river chemistry variation across hydrologic conditions. Sampling included 21 of Ireland’s 22 largest rivers ranked by discharge, first-order and second-order streams draining bog lands, a second-order stream draining a limestone catchment, and downstream transects along the River Shannon. All samples were analyzed for major elements, selected trace elements, and nutrients, and a subset was analyzed for δ34SSO4. New hydrological insights: Most catchments were dominated by carbonate weathering with little contribution from the weathering of aluminosilicates. River water composition also varied geographically along the prevailing wind direction due to inputs from marine aerosols, with additional weathering components important in some systems. Seasonal influences could be seen in the chemistry of the headwaters of the River Shannon, while the lower reaches of the river exhibited less variable behavior throughout seasonal changes, likely due to the influence of lakes in the River Shannon system.

Abstract Background Rhodopseudomonas palustris is a versatile microbe that encounters an innate redox imbalance while growing photoheterotrophically with reduced substrates. The resulting excess in reducing equivalents, together with ATP from photosynthesis, could be utilized to drive a wide range of bioconversions. The objective of this study was to genetically modify R. palustris to provide a pathway to reduce n-butyrate into n-butanol for maintaining redox balance. Results Here, we constructed and expressed a plasmid-based pathway for n-butanol production from Clostridium acetobutylicum ATCC 824 in R. palustris. We maintained the environmental conditions in such a way that this pathway functioned as the obligate route to re-oxidize excess reducing equivalents, resulting in an innate selection pressure. The engineered strain of R. palustris grew under otherwise restrictive redox conditions and achieved concentrations of 1.5 mM n-butanol at a production rate of 0.03 g L−1 day−1 and a selectivity (i.e., products compared to the consumed substrate) of close to 40%. Since the theoretical maximum selectivity is 45%, the engineered strain converted close to its maximum selectivity. Conclusions The innate redox imbalance of R. palustris can be used to drive the reduction of n-butyrate into n-butanol after expression of a plasmid-based enzyme from a butanol-producing Clostridium strain.

Fluoroscopy poses an occupational hazard to orthopedic surgeons. The purpose of this study was to examine resident and faculty understanding of radiation safety and to determine whether or not a radiation safety intervention would improve radiation safety knowledge. An anonymous survey was developed to assess attitudes and knowledge regarding radiation safety and exposure. It was distributed to faculty and residents at an academic orthopedic program before and after a radiation safety lecture. Pre- and post-lecture survey results were compared. 19 residents and 22 faculty members completed the pre-lecture survey while 11 residents and 17 faculty members completed the post-lecture survey. Pre-lecture survey scores were 48.3% for residents and 49.5% for faculty; post-lecture survey scores were 52.7% and 46.1% respectively. Differences between pre and post-survey scores were not significant. This study revealed low baseline radiation safety knowledge scores for both orthopedic residents and faculty. As evidence by our results, a single radiation safety information lecture did not significantly impact radiation knowledge. Radiation safety training should have a formal role in orthopedic surgery academic curricula.

Cave ice can contain a wealth of paleo-climatic and geochemical information that is rapidly being lost with the melting of the temperate zone cryosphere. The karst areas of Slovenia host over 260 ice caves. We collected samples for stable water isotope, major ion, and nutrient analyses from two Slovenian ice caves. Samples included two shallow ice cores in Snežna Cave, collected »5 m apart, and an ice face profile in Ivačičeva Cave. All ice isotopic ratios reflected modern precipitation that could be described by high-elevation meteoric water lines. An offset suggested that fractionation and mixing processes of melted ice affected the isotopic signals. Cation concentrations of ice in both caves showed Ca » Mg>Na>K. The high Ca2+ and Mg2+ contents and elevated HCO3- concentrations indicate that CaCO3 dissolution within the local karst landscape is a primary control on ice chemistry. Low concentrations and inconsistent profile patterns of other major ions and nutrients suggest atmospheric deposition and vadose zone leaching were also primary sources of ions to the ice. Differences in Cl- and SO4 2- profile concentrations at similar depths in Snežna Cave imply that ice melting, water mixing, and re-freezing processes can affect the primary climatic signal stored in the ice. While temperate ice caves can be repositories of climatic information, secondary diagenetic processes that affect ice chemical composition alter the original signal. In addition to chemical analysis, physical processes within the caves must be studied at a small spatial scale to understand and interpret ice chemistry. [ABSTRACT FROM AUTHOR]

Cave ice samples collected within karstic terrain have major ion and nutrient concentrations showing that the ice originates from local precipitation modified by the addition of Ca2+ and HCO3− from the dissolution of the local bedrock. Isotopic profiles of Paradana Cave ice are similar to those described in other ice caves in central and eastern Europe, where the profiles are developed through the freezing of cave pool or “lake„ waters from the top downward during the onset of the cold portion of the year. Stable isotope data suggest future studies may yield a long-term paleo-environmental record for this location.

Rhodopseudomonas palustris has emerged as a model microbe for the anaerobic metabolism of p-coumarate, which is an aromatic compound and a primary component of lignin. However, under anaerobic conditions, R. palustris must actively eliminate excess reducing equivalents through a number of known strategies (e.g., CO2 fixation, H2 evolution) to avoid lethal redox imbalance. Others had hypothesized that to ease the burden of this redox imbalance, a clonal population of R. palustris could functionally differentiate into a pseudo-consortium. Within this pseudo-consortium, one sub-population would perform the aromatic moiety degradation into acetate, while the other sub-population would oxidize acetate, resulting in a single-genotype syntrophy through acetate sharing. Here, the objective was to test this hypothesis by utilizing microbial electrochemistry as a research tool with the extracellular-electron-transferring bacterium Geobacter sulfurreducens as a reporter strain replacing the hypothesized acetate-oxidizing sub-population. We used a 2x4 experimental design with pure cultures of R. palustris in serum bottles and co-cultures of R. palustris and G. sulfurreducens in bioelectrochemical systems. This experimental design included growth medium with and without bicarbonate to induce non-lethal and lethal redox imbalance conditions, respectively, in R. palustris. Finally, the design also included a mutant strain (NifA*) of R. palustris, which constitutively produces H2, to serve both as a positive control for metabolite secretion (H2) to G. sulfurreducens, and as a non-lethal redox control for without bicarbonate conditions. Our results demonstrate that acetate sharing between different sub-populations of R. palustris does not occur while degrading p-coumarate under either non-lethal or lethal redox imbalance conditions. This work highlights the strength of microbial electrochemistry as a tool for studying microbial syntrophy.