Mean Survivorship Research Articles

Mediterranean octocoral populations exposed to marine heatwaves are less resilient to disturbances.

The effects of climate change are now more pervasive than ever. Marine ecosystems have been particularly impacted by climate change, with marine heatwaves (MHWs) being a strong driver of mass mortality events. Even in the most optimistic greenhouse gas emission scenarios, MHWs will continue to increase in frequency, intensity and duration. For this reason, understanding the resilience of marine species to the increase of MHWs is crucial to predicting their viability under future climatic conditions. In this study, we explored the consequences of MHWs on the resilience (the ability of a population to resist and recover after a disturbance) of a Mediterranean key octocoral species, Paramuricea clavata, to further disturbances to their population structure. To quantify P. clavata's capacity to resist and recover from future disturbances, we used demographic information collected from 1999 to 2022, from two different sites in the NW Mediterranean Sea to calculate the transient dynamics of their populations. Our results showed that the differences in the dynamics of populations exposed and those not exposed to MHWs were driven mostly by differences in mean survivorship and growth. We also showed that after MHWs P. clavata populations had lower resistance and slower rates of recovery than those not exposed to MHWs. Populations exposed to MHWs had lower resistance elasticity to most demographic processes compared to unexposed populations. In contrast, the only demographic process showing some differences when comparing the speed of recovery elasticity values between populations exposed and unexposed to MHWs was stasis. Finally, under scenarios of increasing frequency of MHWs, the extinction of P. clavata populations will accelerate and their capacity to resist and recover after further disturbances will be hampered. Overall, these findings confirm that future climatic conditions will make octocoral populations even more vulnerable to further disturbances. These results highlight the importance of limiting local impacts on marine ecosystems to dampen the consequences of climate change.

Nutritional Evaluation of Short-horned Grasshopper (Oxya hyla hyla Serville) as a Substitute for Soybean Meal in Compound Diets of Rohu (Labeo rohita Hamilton)

The growth effects of partial substitution of soybean meal for grasshopper meal (Oxya hyla hyla) in compound diets of Rohu fish (Labeo rohita) were evaluated for 75 days at the aquaculture research center in IAAS, Paklihawa Campus with 16 meshed cages of 1 m3 size, stocked with 12 fingerlings. Completely Randomized Design was used with 4 treatments and 4 replications. Treatments included the incremental substitution of Soybean meal (SM) for Grasshopper meal (GM) as 0% GM, 10% GM, 20% GM and 30% GM. Feeding rates were adjusted every month based on observed body weight. Fish parameters were observed at 16, 27, 45, 60 and 75 days after stocking, whereas, the physical water parameters were observed daily. During the study period, the recorded mean water temperature, pH, dissolved oxygen and survivorship were 19°C, 8.2, 6.4 mg/L and 64.6% respectively. Average growth rate, relative growth rate, specific growth rate, daily weight gain and protein efficiency ratio showed no significant difference (p>0.05) among the treatments. The Feed Conversion Ratio of 20% GM and 30% GM were statistically similar and superior to 0% GM and 10% GM as well. To sum up, we did not have enough evidence to prove the superiority of grasshopper meal incorporated diet on rohu, perhaps because of a lower feed efficiency.

Describing the dynamics of recruits and juvenile scleractinian corals using 3d models: a case study from Cayo Mero reef, Morrocoy National Park, Venezuela

Understanding the dynamics of coral recruitment and post-settlement is fundamental to a better comprehension of coral reef dynamics and recovery. We studied the abundance and survivorship of coral recruits and juveniles together with benthic dynamics at a scale of months and centimeters in Playa Mero reef, a disturbed reef in Morrocoy National Park. For this, we used photogrammetry to monitor eight permanent 50x50 cm quadrats haphazardly deployed every 3–4 months over 18 months. Juveniles and recruits of Agaricia spp. were at least four times more abundant than reef builders such as Orbicella spp. A distance-based linear model showed that rugosity, macroalgae, coral cover, and sand were the most important benthic variables and predicted up to 46% of the spatial and temporal variation of recruit and juvenile corals. The mortality of juvenile corals was higher than net recruitment rates, and only a limited number of genera such as Agariciids, Colpophyllia, Porites, and Scolymia were observed as recruits. Using a logit model, we also found a positive relationship between the mean growth rate and survivorship of juvenile corals (Nagelkerke R2= 0.67). We concluded the lack of recruitment of large reef builders, and the rapid mortality of a limited number of juvenile species, might be a sign of a coral community's failure to increase coral cover.

LINER EXCHANGE WITH HIGHLY CROSSLINKED POLYETHYLENE FOR WEAR AND OSTEOLYSIS: DOES FIXATION METHOD MATTER?

Isolated liner exchange with highly crosslinked polyethylene (HXLPE) is an option to address polyethylene wear and osteolysis after total hip arthroplasty (THA). The liner can be fixed with either the original locking mechanism or cemented into the acetabular cup. Whether the method used for fixation of HXLPE liner has any bearing on the outcomes 10 to 15 years after surgery is still unclear.Data for all patients who had undergone isolated liner exchange surgery with HXLPE in our institution between August 2000 and January 2015 were retrieved. Patients were classified according to the locking mechanism used (original locking mechanism or cemented). Survivorship and revision rates were compared among different subgroups. A total of 86 isolated liner exchanges were performed and patients had a mean duration of follow-up of 13 years (range, 5 to 22). 50 patients had the new liner cemented and the other 36 patients used the original locking mechanism.20 patients (23.3%) had complications, with dislocation being the most common (7). 10 of them (12.6%) required re-revision surgery. Overall estimated mean survivorship was 19.2 years. There was no significant difference in the re-revision rate between original locking mechanism (11.1%) and cementation (12.0%) for the fixation of HXLPE (p=0.899). Using the Kaplan-Meier survival analysis, the revision-free survival of HXLPE fixed with original locking mechanism and cementation were 94.1% and 93.2%, respectively, at 10 years, and were 84.7% and 81.3%, respectively, at 20 years (p=0.840).The re-revision rate and the revision-free survival of liner exchange surgery using HXLPE liner were not affected by the fixation technique used. Both cementing a HXLPE liner or using the original locking mechanism were associated with good survivorship at 13 years follow up.

Diols and sugar substitutes in attractive toxic sugar baits targeting Aedes aegypti and Aedes albopictus (Diptera: Culicidae) mosquitoes.

Around the world, mosquitoes continue to transmit disease-causing pathogens and develop resistance to insecticides. We previously discovered that a generally regarded as safe (GRAS) compound, 1,2-propanediol, reduces adult mosquito survivorship when ingested. In this study, we assess and compare 5 more chemically related compounds for mosquito lethality and 8 GRAS sugar substitutes to determine toxicity. We conducted a series of feeding assays to determine if ingesting the compounds influenced mosquito mean survivorship in locally collected lab-reared populations of Aedes aegypti (Diptera, Culicidae, Linnaeus, 1762) and Aedes albopictus (Diptera, Culicidae, Skuse, 1894) mosquitoes. Our results indicate that 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, DL-dithiothreitol, acesulfame potassium, allulose, erythritol, sodium saccharin, stevia, and sucralose significantly reduced the mean survivorship of one or both species. Short-term trials with the most toxic compounds revealed that they could substantially affect survivorship after 24 h. We also found that there were different responses in the 2 species and that in several experimental conditions, male mosquitoes expired to a greater extent than female mosquitoes. These findings indicate that several of the compounds are toxic to mosquitoes. Further study is required to determine their effectiveness in attractive toxic sugar baits (ATSBs) as a potential component of population control strategies.

Lateral Patella Facet Osteoarthritis is Not Contraindicated for Medial UKA: Mean 10-Year Outcomes and Survivorship

Lateral Patella Facet Osteoarthritis is Not Contraindicated for Medial UKA: Mean 10-Year Outcomes and Survivorship

Effect of Substratum Structural Complexity of Coral Seedlings on the Settlement and Post-Settlement Survivorship of Coral Settlers

The substratum structure is critical for facilitating settlement and increasing the survivorship of coral settlers. However, knowledge about its structural complexity is largely lacking. In this study, we examined the effect of complexity on the settlement and post-settlement survivorship of coral settlers using four types of structures: groove, using a CSD (Coral Settlement Device, 4.5 cm φ × 2.5 cm H, top-shaped ceramic); flat, using a CP (Ceramic Plate, 29.5 cm L × 3.1 cm W × 0.9 cm H, unglazed ceramic plate); linear, using a CN (Coral Net, mesh size 19 mm, biodegradable plastic net); and wrinkle, using a SS (Scallop Shell, 11.0 cm in shell length). The complexity was obtained from the ratio of the surface area to the vertically projected area of the substratum. The substratum sets were installed in the coral reef around the Ryukyu Islands every May from 2012 to 2014. After about 2 or 6 months of spawning, a certain number of substratum types were sampled, and the number of coral spats that settled on them was counted by taxa classified into Acropora, Pocilloporidae, Millepora, and Others. The larval settlement rate in the first set of samples and the survivorship of coral spats in the second set of samples were estimated. The mean settlement rate was, in order, the CSD; SS; CN; and CP, and the mean survivorship was, in order, the CSD; CP; SS; and CN, over three years. A positive correlation was found between the structural complexity, mean settlement rate, and mean survivorship. Our results show that the structural complexity of coral seedlings affects the settlement of coral larvae and the survivorship of coral spats.

Isolated Liner Exchange in Total Hip Arthroplasty at a Mean of 13 Years of Follow-up: Does Fixation Technique Matter?

BackgroundIsolated liner exchange is an option to address polyethylene wear after total hip arthroplasty (THA). The liner can be fixed with either the original locking mechanism or cemented into the acetabular cup. Whether the method used for liner fixation has any bearing on the outcomes in the first and second decade after surgery is still unclear. MethodsData for all patients who had undergone isolated liner exchange surgery in our institution between April 1995 and January 2015 were retrieved. Patients were classified according to the type of polyethylene liner (conventional or highly crosslinked polyethylene) and the locking mechanism used (original locking mechanism or cemented). Survivorship and revision rates were compared among different subgroups. A total of 118 isolated liner exchanges were performed and patients had a mean duration of follow-up of 13 years (range, 5 to 25). ResultsOverall estimated mean survivorship was 17 years. Use of highly crosslinked polyethylene (HXLPE) had a lower re-revision rate compared to conventional liners (10.5 versus 46.9%) (P < .001). The re-revision rate of exchanges using HXLPE was not affected by the type of fixation (original locking mechanism 11.1 versus cement 10.0%, P = .868). Conversely, using the original locking mechanism with a conventional liner had a higher re-revision rate compared to cemented conventional liners (58.3 versus 12.5%) (P = .024). ConclusionHXLPE liners should be used in insert exchange surgery whenever possible. Re-revision rate of exchanges using HXLPE was not affected by the fixation technique used. Cementing an insert into an acetabular component is associated with good survivorship at a mean of 13 years follow-up.

Tapered Modular Femoral Stems for Revision Total Hip Arthroplasty Show Excellent Mid-Term Survivorship.

Revision total hip arthroplasty (THA) can be challenging in the face of proximal femoral bone loss, catastrophic implant failure, or recurrent hip instability. Tapered modular femoral stems have shown substantial success at short follow up for aseptic revisions. The purpose of this study was to report mid-term revision THA outcomes of a tapered modular femoral stem at a tertiary referral center used to treat both aseptic as well as periprosthetic joint infections (PJIs). We specifically sought to assess: (1) revision-free implant survivorship; (2) patient-reported outcome measurements (i.e., Hip Disability and Osteoarthritis Outcome Score, Joint Replacement [HOOS JR]); (3) postoperative surgical complications and 30-day readmissions; as well as (4) radiographic outcomes. We reviewed a consecutive series of 92 patients who underwent revision THA between 2009 and 2013 with a tapered modular femoral stem. After accounting for mortality (n=7) and loss to follow up (n=13), a total of 72 implants in 66 patients who had eight years of mean follow up (range, 2 to 11) were included. PJI (46%) was the predominant preoperative indication for revision THA, followed by aseptic loosening (25%), periprosthetic fracture (18%), and symptomatic hardware (10%). Outcomes of interest included all-cause revision-free survivorship, postoperative complications, and HOOS JR, as well as SF-12 scores. Radiographically, they were evaluated for subsidence, radiolucencies, and loosening. Aseptic revision-free survivorship of the femoral component was 95.8% (69 out of 72). Including septic cases, revision-free survivorship was 87.5% (63 cases), and 60 implants (83.3%) had an all-cause revision-free survivorship. For those patients who underwent septic revisions, eight out of nine remained infection free, while one underwent a resection arthroplasty. Furthermore, the cause for femoral aseptic revisions were subsidence (1.4%) and aseptic loosening (2.8%). Functional score improvements for HOOS JR, SF-12 PCS, as well as MCS were 29, 13, and 2, respectively (all p<0.001). There were eight emergency department visits (11.1%,) and six inpatient readmissions (8.3%). Additionally, two patients had dislocations (2.8%, two out of 72) not requiring revision. There were two cases of femoral subsidence and one aseptic loosening requiring revision; whereas, the rest did not demonstrate any progressive radiographic lucencies. The eight-year mean survivorship results of the tapered modular femoral stems in revision THA demonstrated excellent results. Our series found improved outcome scores and relatively low postoperative complications, which indicate a favorable implant survivorship profile for revision THA. These results serve to inform arthroplasty surgeons of expected outcomes of the modular stems when used for patients who need complex revision THA.

Outcomes Of The Combined Anteroposterior Approach For Forequarter Amputation In Shoulder Girdle Tumours.

Forequarter amputation (FQA) is the surgical treatment of choice for tumours in the upper extremity and shoulder girdle that infiltrate the neurovascular bundle, shoulder joint and muscles of the shoulder girdle in non-salvageable cases. In both curative and palliative settings, FQA can serve as an effective oncological treatment for local control of tumour. All patients who underwent FQA in our unit from January 2016 till August 2019 for oncological indications were included in our study and their clinical outcomes were calculated. Thirteen patients were included in the study including 8 male patients. Mean age of patients at surgery was 20 years (Range 10-53 years) with a minimum follow up of 6 months or till patient was deceased earlier. Six patients had primary osteosarcoma, 4 had Ewing's sarcoma, 2 had Spindle cell sarcoma while 1 had Giant cell tumour. Six patients underwent surgery with curative intent. No major per operative complication was encountered in any of the cases with a mean blood loss of 350 ml and mean duration of surgery being 75 minutes. At last, follow up only 6 patients were alive, with 2 patients alive with disease (Metastasis) and undergoing palliative treatment. None of our patients had local recurrence. Mean survivorship for the whole cohort was 9.2 months (Range 3-18 months) with a mean survivorship for the deceased group was 7.1 months (Range 3-16 months) and mean survivorship for alive patients was 11.6 months (range 9-18 months). All the alive patients had phantom limb sensations and only one had a prosthesis in place only for cosmetic reasons, at last follow up. Although FQA is a significantly body disfiguring procedure, but in large tumours of shoulder girdle, this is a viable option for local control of the disease. Based on our study, although relatively small sample size, we propose the combined anteroposterior approach to be safe and reliable for advanced shoulder girdle tumours.

Naturally Occurring Rock Type Influences the Settlement of Fucus spiralis L. zygotes

The settlement of spores and larvae on hard substrates has been shown to be influenced by many factors, but few studies have evaluated how underlying bedrock may influence recruitment. The characteristics of coastal rock types such as color, heat capacity, mineral size, and free energy have all been implicated in settlement success. We examined the influence of naturally occurring rock types on the initial attachment of zygotes of the brown alga Fucus spiralis Linnaeus 1753. We also assessed the dislodgment of zygotes on four bedrock types after initial attachment in laboratory experiments using wave tanks. Settling plates were prepared from limestone, basalt, schist, and granite, found in the region of Orrs Island, Maine, USA. The plate surfaces tested were either naturally rough or smooth-cut surfaces. We measured the density of attached zygotes after 1.5 h of settlement and subsequently after a wave treatment, in both winter and summer. The pattern of initial attachment was the same on natural and smooth surfaces regardless of season: highest on limestone (range 7.0–13.4 zygotes/cm2), intermediate on schist (1.8–8.5 zygotes/cm2) and basalt (3.5–14.0 zygotes/cm2), and lowest on granite (0.8–7.8 zygotes/cm2). Patterns of survivorship following the wave treatment were similar to those of initial settlement with the mean survivorship varying from 60.1% (SE = 3.8) (limestone, smooth substrate) to 31.8% (SE = 0.59) (granite, natural substrate), and with the highest mean survival on limestone, basalt, and schist, and the lowest on granite. Our results suggest that rock type has a significant effect on zygote attachment and persistence. Patterns of attachment were the same on smooth and rough surfaces, indicating that surface roughness is not the predominant factor controlling the difference in successful attachment among rock types. Other properties of bedrock, possibly grain size, surface free energy, or chemical interaction with the adhesives used by the zygotes, directly affect the attachment of these algal propagules. These results suggest that patterns of benthic community structure could be determined in part by the distribution of bedrock types.

Long-Term Survivorship of Modular Cementless Femoral Stem in Complex Primary Total Hip Arthroplasty: A Concise Minimum 15-Year Follow-Up Report

BackgroundS-ROM hip is a well-established and versatile prosthesis that offers extensive metaphyseal and diaphyseal geometries providing solutions for a variety of surgical scenarios. The aim of this study is to report on long-term survivorship and radiographic outcomes of complex primary total hip arthroplasty (THA) using a modular cementless stem (S-ROM). MethodsRetrospective consecutive study was conducted of 167 patients (167 hips): 97 males and 70 females with average age at the time of surgery of 55 years (range 22-76). All patients underwent complex THA by the senior author from 1987 to 1999. Patients were identified using a prospective database. Demographic, clinical, and surgical data were collected from health records. All patients received a cementless acetabular component with a standard polyethylene liner. The primary outcome measure was survivorship beyond 15 years using stem revision for any cause as an end point. Secondary outcome measure was rate of radiographic loosening using Engh classification. ResultsOnly 3 patients required stem revision for aseptic loosening and 1 for periprosthetic fracture. Isolated acetabular revision was undertaken in 23 of 167 patients (13.8%) due to polythene wear, osteolysis, and aseptic loosening. Proximal femoral stress shielding (zone 1, 7) was noted in 34 of 167 hips (20.4%). Stable bony ingrowth was noted in 144 hips (86.2%) and the remaining 23 hips had stable fibrous ingrowth (13.8%). Using stem “any-cause revision” as an endpoint, the mean stem survivorship was 31.5 years (95% confidence interval 31.007-31.985) with 30-year estimated survivorship of 97.6%. ConclusionIn a single designer surgeon series, S-ROM stem has stood the test of time with long-term, 30-year survivorship of 97.6% and continues to play an important role in modern hip surgery providing longevity and versatility. However, further comparative long-term studies from independent centers are needed for a definitive conclusion. Level of EvidenceIV.

Comparing Selected Life-History Traits of Black Soldier Fly (Diptera: Stratiomyidae) Larvae Produced in Industrial and Bench-Top-Sized Containers

As global food demand is increasing along with human population growth, there is a greater need for alternative protein sources. Insect protein, especially the larvae of the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), has become a key approach for solving this issue in part due to its ability to convert organic waste into insect biomass with minimal resource (e.g., land, water) requirements. However, most information utilized to develop industrial production of this species is reliant on data generated from laboratory-scaled studies. Unfortunately, scaling these data to an industrial level potentially is not linear resulting in over, or under, estimating production. In this study, we compared selected life-history traits of larval black soldier fly produced at benchtop (e.g., 1 liter container with 614 larvae) and industrial scales (e.g., 29.5 liter container inoculated with 10,000 larvae). Larvae were provided a single feeding (2 g/larva) in each treatment. Significant differences in the mean larval weight (24.7%), survivorship (−28.2%), and biomass conversion (−2.7%) were determined between benchtop and industrial treatments. These results indicate larval number and the associated container size are important factors to consider when designing a black soldier fly factory. Furthermore, caution should be taken when applying data from laboratory studies to industrial scale production systems as the values potentially are not linear.

High survivorship rate and good clinical outcomes at mid-term follow-up for lateral UKA: a systematic literature review.

The purpose of this paper is to systematically review the available literature to understand the effectiveness, the survivorship, the clinical outcomes and the complications of lateral UKA. A review of the current literature available about lateral UKA was performed in March 2020, according to the PRISMA guidelines. Selection was based on the following inclusion criteria: (1) clinical reports of any level of evidence, (2) written in English language, (3) published from 1996 to 2020, (4) dealing with clinical data on lateral UKA. A total of 47 articles, published between 1996 and 2020, were included in the review. Quality of every article was assessed using the Modified Coleman Methodology Score. A total of 47 studies were included. Mean mCMS was 45.27 (range 30-62). Mean age at surgery was 64.5years (range 34.1-88.0years). In 1741 patients (65.5%) a metal back implant was used and in 421 patients (15.8%) an all poly design was used. Several scores were used to evaluate clinical results (OKS, AKSS, IKS, KOOS, WOMAC, VAS). Range of motion improved with an overall mean value of 120.3° (range: 105.9°-143.3°). The mean follow-up was 60.7months (range, 7-204months), mean survivorship (absence of a revision) with a minimum 60months of follow-up was 88.6% (range 74.5-100) and mean satisfaction of patients was 78.5% (range 41.0-97.9). Lateral UKA seems to be an effective solution to manage lateral osteoarthritis (OA), based on preliminary results, with survivorship and satisfaction rate comparable to medial UKA and total knee arthroplasty (TKA). Nonetheless, this review highlights that the quality of studies available in current literature is low. Systematic review of level IV studies.

Modifications of the pirogoff amputation technique in adults: A retrospective analysis of 123 cases

BackgroundThe Pirogoff amputation (1854) was initially developed to provide full-weight-bearing stumps and therefore allow a short ambulation without prosthesis. Modifications of the original technique including Boyd (1939) and the “Modified Pirogoff” were developed, which further reduced complications and improved the outcome. However, the current evidence regarding the techniques is scarce. The functional outcome, survivorship and complication rates are unknown. It was the purpose of this study to expand the knowledge with a retrospective case series and ultimately summarize and analyze the data with a systematic review. MethodsA retrospective study of the Boyd procedures from our institution between 1999 and 2018 was performed. Outcome was determined based on the PLUS-M Score (Prosthetic Limb Users Survey of Mobility). Survivorship (absence of more proximal amputation), postoperative leg-length discrepancy, time to early fusion and time to mobilization were also evaluated. Finally, in the second part of the study, the results were integrated in a systematic review, which followed the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines. The quality of all the studies were then assessed using the Joanna Briggs Institute Critical Appraisal Checklist (JBI CAC). ResultsA total of 123 procedures including 115 patients, with an average follow-up of 45 months (range, 10–300 months) could be included. A very good or good function could be achieved in 85 (69%) patients. The mean survivorship was 82.1% (range 46%–100%). In four studies, including our series, all patients remained with a functional stump at the latest follow-up. The calculated average leg-length discrepancy was 2.5 cm. ConclusionThe “Modified Pirogoff” and Boyd amputation techniques can achieve favourable long-term functional outcome in cases of irreparable foot conditions such as osteomyelitis or trauma. Patency of the posterior tibial artery is an indispensable condition to elect for these surgical techniques. Presence of neuropathy does not preclude this amputation level. With proper patient selection, a maximal survivorship of the stump with treatable minor complications can be achieved.Level of Evidence: IV.

Coral Translocation as a Method to Restore Impacted Deep-Sea Coral Communities

Corals and sponges in rocky deep-sea environments are foundation species postulated to enhance local diversity by increasing biogenic habitat heterogeneity and enriching local carbon cycling. These key groups are highly vulnerable to disturbances (e.g., trawling, mining, and pollution) and are threatened by expansive changes in ocean conditions linked to climate change (acidification, warming, and deoxygenation). Once damaged by trawling or other disturbances, recolonization and regrowth may require centuries or longer, highlighting the need for stewardship of these deep-sea coral and sponge communities (DSCSCs). To this end, the sustainability of DSCSCs may be enhanced not only by protecting existing communities, but also repopulating disturbed areas using active restoration methods. Here, we report one of the first studies to explore methods to restore deep-sea coral populations by translocating coral fragments of multiple coral species. Branches of deep-sea corals were collected by ROV from 800–1300 m depth off central California and propagated into multiple fragments once at the surface. These fragments were then attached to “coral pots” using two different methods and placed in the same habitat to assess their survivorship (n=113 total fragments, n=7 taxa, n=7 deployment groups). Mean survivorship for all translocated coral fragments observed within the first 365 days was ~52%, with the highest mortality occurring in the first 3 months. In addition to an initial temporal sensitivity, survival of coral fragments varied by attachment method and among species. All coral fragments attached to coral pots using zip ties died, while those attached by cement resulted in differential survivorship over time. The latter method resulted in 80–100% fragment survivorship after one year for Corallium sp., Lillipathes sp., and Swiftia kofoidi, 12–50% for the bamboo corals Keratoisis sp. and Isidella tentaculum, and 0–50% for the bubblegum corals Paragorgia arborea and Sibogagorgia cauliflora. These initial results indicate differences in sensitivities to transplanting methods among coral species, but also suggest that repopulation efforts may accelerate the recovery of disturbed DSCSCs.

Periodic catastrophes over human evolutionary history are necessary to explain the forager population paradox

The rapid growth of contemporary human foragers and steady decline of chimpanzees represent puzzling population paradoxes, as any species must exhibit near-stationary growth over much of their evolutionary history. We evaluate the conditions favoring zero population growth (ZPG) among 10 small-scale subsistence human populations and five wild chimpanzee groups according to four demographic scenarios: altered mean vital rates (i.e., fertility and mortality), vital rate stochasticity, vital rate covariance, and periodic catastrophes. Among most human populations, changing mean fertility or survivorship alone requires unprecedented alterations. Stochastic variance and covariance would similarly require major adjustment to achieve ZPG in most populations. Crashes could maintain ZPG in slow-growing populations but must be frequent and severe in fast-growing populations-more extreme than observed in the ethnographic record. A combination of vital rate alteration with catastrophes is the most realistic solution to the forager population paradox. ZPG in declining chimpanzees is more readily obtainable through reducing mortality and altering covariance. While some human populations may have hovered near ZPG under harsher conditions (e.g., violence or food shortage), modern Homo sapiens were equipped with the potential to rapidly colonize new habitats and likely experienced population fluctuations and local extinctions over evolutionary history.

Eight-year results of transtibial nonanatomic single-bundle versus double-bundle anterior cruciate ligament reconstruction: Clinical, radiologic outcomes and survivorship.

To compare the long term outcomes of transtibial nonanatomic single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. Between January 2008 and September 2010, we retrospectively evaluated 377 patients who underwent primary ACL reconstruction and who were available at 8 years of follow-up. Patients who received transtibial nonanatomic SB ACL reconstruction ( n = 263) were assigned to group SB and DB ACL reconstruction ( n = 114) to group DB. The patients were assessed with the International Knee Documentation Committee (IKDC), the Lysholm scores, Tegner activity score, knee joint stability tests, and patellofemoral osteoarthritis (OA) findings using the Kellgren-Lawrence (K-L) classification. Contralateral ACL (CACL) injury was also evaluated. Thirteen patients underwent revision ACL surgery during the follow-up. Ultimately, 256 patients in group SB and 108 patients in group DB were available at the 8-year follow-up. At final follow-up, the IKDC subjective score ( p = 0.04) and Lysholm score ( p = 0.02) showed significantly superior results in group DB compared to group SB. However, there was no significant difference of Tegner activity score ( p = 0.30), range of motion ( p = 0.81), and knee joint stability tests. There was significant progression of patellofemoral OA between preoperative and final follow-up in ipsilateral knee of both groups but not significant progression in contralateral knee. However, there was no significant difference between the two groups at the follow-up. There were 2.7% ipsilateral ACL graft failure in group SB, compared with 5.2% in group DB ( p = 0.12) and 6.4% CACL tear in group SB, compared with 5.2% in group DB ( p = 0.65). The mean survivorship of ACL graft was 9.47 ± 0.05 years (95% confidence interval (CI), 9.36-9.58) in group SB and 9.87 ± 0.16 years (95% CI, 9.54-10.20) in group DB, and there was no significant difference ( p = 0.25). DB ACL reconstruction resulted in significantly better clinical IKDC subjective scores and Lysholm scores. However, most of the differences in clinical scores were small, and the clinical relevance of this difference is unknown. In addition, there was no significant difference in Tegner activity score, knee joint stability tests, patellofemoral OA, and survivor rate of the ACL graft and CACL after reconstruction after a minimum of 8-year follow-up. Level of Evidence: Cohort study; level of evidence, 3.

Interprosthetic Femoral Sleeves in Revision Arthroplasty: A 20-Year Experience

BackgroundInterprosthetic femoral fractures in patients with ipsilateral stemmed total hip arthroplasty (THA) and total knee arthroplasty (TKA) can be technically demanding to treat surgically. Nonunion and implant failure are among the main complications following fixation of interprosthetic femoral (IF) fractures. Total femoral arthroplasty (TFA) is associated with a high incidence of infection and instability. IF sleeves have been designed to avoid the disadvantages of these techniques and to provide a stable construct. The aim of this study was to present the results with this device from a single center. MethodsWe reviewed 26 patients who underwent revision arthroplasty procedures, using custom-made cemented IF sleeves between 1997 and December 2017 in our institution. Two-part sleeves were used in 18 patients and one-part sleeves in 8 patients. The most common indication was an IF fracture (18 patients). Patients were monitored for postoperative complications, implant failure, and re-revision. The minimum follow-up of the survivors with nonrevised sleeves was 12 months. ResultsTwenty-three patients were included for the final analysis. The mean survivorship of the IF sleeve was 4.6 years at latest follow-up (mean 48.5 months; range 12 to 156). The overall rate of complications was 47.8%. The rate of mechanical failure was 21.7%. Late infections occurred in 3 patients (13%). At the latest follow-up, the mean Harris Hip Score was 69.9 points (range 39 to 94), and the mean functional Knee Society Score was 42.5 points (range 0 to 90), with average knee flexion of 95° (range 90° to 100°). ConclusionThe IF sleeve is a valid technique for the management of selected patients with IF fractures, particularly when a stable fracture fixation is not possible. Hip instability is not a concern, and functional improvement is achievable. Careful planning is required preoperatively to avoid mechanical failure.

Twenty-year survivorship of tree seedlings in wind-created gaps in an upland hardwood forest in the eastern US

Wind is a common canopy disturbance in the upland oak (Quercus)- and hickory (Carya)-dominated stands of the Central Hardwood Region of the eastern US. Canopy openings range from small gaps, resulting from windthrow of single dominant trees, to occasional large gaps of many hectares formed by straight-line winds associated with severe thunderstorms and rare subtropical hurricanes. Vegetation regeneration response in small gaps and larger artificially created (i.e., timber harvested) gaps has been extensively studied, but little has been reported on naturally formed large gaps (> 6 trees) where a partial canopy typically remains from residual overstory and midstory trees. We investigated advance regeneration survivorship on a landscape scale within and around 12 large wind-felled gaps created by Hurricane Opal (October 1995) in a Southern Appalachian watershed. We hypothesized that survivorship would (1) change along a linear distance gradient from the unaffected forest towards gap center (2) vary in relation to categorical gap locations-within-gaps versus in the adjacent unaffected forest and (3) be affected by vegetation and environmental variables. In early 1996 we tagged tree seedlings in quadrats located along linear axes that extended from gap center into the unaffected forest and measured a variety of vegetation and environmental variables. Overall mean survivorship declined from 1997 (0.96) to 2016 (0.56). We found that survivorship was related to linear distance gradients for species rated intermediate in shade tolerance, such as red oaks, but not for shade intolerant, tolerant, and semi-tolerant species (e.g. white oaks). We found that survivorship increased on a linear distance gradient from gap center into the unaffected forest over the first 9 years of our investigation. By year 20 this relationship had reversed: survivorship increased from the unaffected forest to gap centers. Survivorship was also modeled as a function of categorical location of tagged seedlings within-gaps versus in the unaffected forest. Again, we found that survivorship of only intermediate shade tolerant species was related to categorical locations. Survivorship decreased in relation to time and cohort competition and increased with initial seedling height. Our 20-year investigation revealed changes in dynamics of regeneration that would not have been apparent in a short-term study. These results will enable resource managers to assess regeneration development in large gaps following windstorms in oak-dominated hardwood stands.