Impact of Psychiatric Symptoms on Nasal Perception in Septorhinoplasty Patients.

Psychological assessment plays a crucial role in the preoperative phase of septorhinoplasty (SRPL), exerting potential influence on both pre- and postoperative aspects of quality of life (QoL). In this prospective study, SRPL patients were systematically screened using two validated questionnaires for body dysmorphic disorder (BDD) and one each for anxiety, depression, and somatic symptom disorder (SSD). Nasal perception was evaluated utilizing two disease-specific, self-report instruments: The Rhinoplasty Outcomes Evaluation (ROE) and the Functional Rhinoplasty Outcome Inventory-17 (FROI-17). A total of 95 patients were enrolled. Positive screening rates were 40.4 and 28.3% for BDD, 37.3% for elevated anxiety, 16.4% for depression, and 22.4% for SSD. Mean scores on the ROE and FROI indicated lower QoL in all positive screening groups. Statistically significant differences were observed for anxiety (FROI total score: 47.1 ± 14.6 to 37.8 ± 16.2; p = 0.021) and BDD (ROE: 43.7 ± 15.7 to 32.5 ± 15.5; p = 0.003 and FROI total score: 47.4 ± 15.3 to 37.8 ± 17.1; p = 0.014). The Hospital Anxiety and Depression Scale exhibited a significant correlation with the preoperative FROI score (r = 0.34, p = 0.005). Patients with positive screenings for depression, anxiety, BDD, and SSD demonstrated compromised QoL during preoperative assessments compared with their negative counterparts, reflecting diminished nasal perception in both esthetic and functional dimensions. Surgeons must be cognizant of these psychological aspects during preoperative evaluations.

Quality of Life Improvement in Concurrent Septorhinoplasty and Endoscopic Sinus Surgery.

OBJECTIVES: Septorhinoplasty (SRPL) and functional endoscopic sinus surgery (FESS) are two frequently performed surgeries to improve quality of life (QoL) in patients with nasal symptoms. It has been demonstrated as a safe combination regarding complication rates, but patient satisfaction in concurrent surgery has not been adequately studied yet. METHODS: Patients undergoing sole FESS due to chronic rhinosinusitis (n = 57), sole SRPL (n = 148), and concurrent surgery (n = 62) were prospectively evaluated for their disease-specific QoL before and one year after surgery. Each procedure was performed by the same surgeon (OCB). For SRPL, the patient-reported outcome measures Rhinoplasty Outcomes Evaluation (ROE) and Functional Rhinoplasty Outcome Inventory (FROI-17) were utilized, and for chronic rhinosinusitis, the Sino-Nasal Outcome Test-22 (SNOT22). RESULTS: All three groups showed significant improvement in the postoperative QoL measurements (all p < 0.01). The postoperative improvements were slightly smaller in the concurrent surgery group compared with the single surgery groups measured with ROE (combined: +55.2 ± 9.3, single: +58.8 ± 9.8, p = 0.02), FROI total score (combined: +47.6 ± 5.2, single: +49 ± 5.4; p = 0.08) and SNOT22 (combined: +33.1 ± 6.7, single +34.5 ± 7, p = 0.26). CONCLUSIONS: SRPL, FESS, and combined surgery improve disease-specific QoL. When applicable, surgeons may offer the benefits of a combined procedure without compromising the QoL gain. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1239-1245, 2024.

Quality of Life and Screening on Body Dysmorphic Disorder, Depression, Anxiety in Septorhinoplasty.

OBJECTIVES: Septorhinoplasty (SRPL) can improve quality of life (QoL) in functional and aesthetical aspects of the nose. A key factor compromising postoperative satisfaction is symptoms of body dysmorphic disorder (BDD), defined by excessive concerns and distress over slight or imagined physical defects. Although a high prevalence of BDD in SRPL patients is evident, the effect of positive screening on BDD and other psychiatric disorders is understudied. It was hypothesized that patients screening positive for BDD, depression or anxiety do not show increased postoperative QoL. METHODS: A multicenter, prospective study including 259 patients. For psychiatric evaluation, the BDD concern questionnaire-aesthetic version and the Hospital Anxiety and Depression Scale were used; for disease-specific QoL the Rhinoplasty Outcomes Evaluation (ROE) and the Functional Rhinoplasty Outcome Inventory (FROI-17). RESULTS: In preoperative evaluation, 32.5% had a positive screening for BDD, 42.2% for increased anxiety, and 32.9% for depression. Mean QoL improved in the whole cohort (FROI total score: 54.4 ± 21.8 to 32.8 ± 23.7 and ROE: 32.3 ± 15.6 to 69.8 ± 23.1, both p < 0.001). Patients screening positive for BDD, depression or anxiety did show an increased postoperative QoL, but to a significantly lower degree and with lower pre- and postoperative QoL levels. CONCLUSIONS: SRPL patients show a high prevalence of BDD symptoms, elevated anxiety, and depression. These subgroups show lower QoL levels and an impaired QoL increase after surgery. Rhinoplasty surgeons must be aware of the disorders and their symptoms, discuss potential concerns with the patients, and potentially refer them to a specialist. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2187-2193, 2024.

Can fractal dimensions objectivize gastropod shell morphometrics? A case study from Lake Lugu (SW China).

Morphometrics are fundamental for the analysis of size and shape in fossils, particularly because soft parts or DNA are rarely preserved and hard parts such as shells are commonly the only source of information. Geometric morphometrics, that is, landmark analysis, is well established for the description of shape but it exhibits a couple of shortcomings resulting from subjective choices during landmarking (number and position of landmarks) and from difficulties in resolving shape at the level of micro-sculpture.With the aid of high-resolution 3D scanning technology and analyses of fractal dimensions, we test whether such shortcomings of linear and landmark morphometrics can be overcome. As a model group, we selected a clade of modern viviparid gastropods from Lake Lugu, with shells that show a high degree of sculptural variation. Linear and landmark analyses were applied to the same shells in order to establish the fractal dimensions. The genetic diversity of the gastropod clade was assessed.The genetic results suggest that the gastropod clade represents a single species. The results of all morphometric methods applied are in line with the genetic results, which is that no specific morphotype could be delimited. Apart from this overall agreement, landmark and fractal dimension analyses do not correspond to each other but represent data sets with different information. Generally, the fractal dimension values quantify the roughness of the shell surface, the resolution of the 3D scans determining the level. In our approach, we captured the micro-sculpture but not the first-order sculptural elements, which explains that fractal dimension and landmark data are not in phase.We can show that analyzing fractal dimensions of gastropod shells opens a window to more detailed information that can be considered in evolutionary and ecological contexts. We propose that using low-resolution 3D scans may successfully substitute landmark analyses because it overcomes the subjective landmarking. Analyses of 3D scans with higher resolution than used in this study will provide surface roughness information at the mineralogical level. We suggest that fractal dimension analyses of a combination of differently resolved 3D models will significantly improve the quality of shell morphometrics.

Quality of life outcome in revision rhinoplasty in regards to number of revision surgeries and cartilage donor site.

OBJECTIVES: Rhinoplasty with or without combined septoplasty is one of the most frequently performed procedures in facial plastic surgery. Patient satisfaction and improvement in quality of life (QoL) is the primary goal. This prospective study was conducted to analyse Qol outcome in revision rhinoplasty in regards to number of revision surgeries and cartilage donor site using patient-reported outcome measures (PROMs). METHODS: Preoperative and at least 12-months postoperative scores on the Nasal Obstruction Symptome Evaluation (NOSE) questionnaire (range 0-100, lower scores indicate better outcome) and the Rhinoplasty Outcomes Evaluation (ROE) questionnaire (range 0-100, higher scores indicates better outcome) were obtained. Additionally, data on age, gender and number of previous rhinoplasties were assessed. All revision rhinoplasties were performed by one surgeon (author, F.R.) between 2014 and 2017. RESULTS: Sixty-four patients (11 (17.2%) male, 53 (82.8%) female) prospectively enrolled in this study. In 41 (64.1%) cases septal cartilage and in 23 (35.9%) patients ear cartilage was the donor site in revision surgery. Patients with more than one previous surgery (n=18) started with a lower preoperative ROE score (28.2 ± 12.8) compared to patients who had received only one previous surgery. The difference however was not significant (p=0.06). This subgroup still showed significant postoperative improvement (ROE-postop 61.9 ± 24.2; p<0.05). Both cohorts (septal cartilage and ear cartilage) improved significantly in regards to their ROE and NOSE scores after surgery and therefore showed improved health-related QoL. We could not detect any differences in health-related QoL postoperatively in regards to cartilage donor site in revision surgery. CONCLUSION: Revision rhinoplasty improves health-related QoL. There are no differences in ROE- or NOSE-scores postoperatively in regards to graft material (ear- versus septal cartilage). Both subgroups show significantly higher scores postoperatively.

Surgical and Nonsurgical Management of the Nasal Skin-Soft Tissue Envelope.

Management of the skin-soft tissue envelope (SSTE) in rhinoplasty is challenging and critical for the overall outcome. The preoperative identification of patients with thick or thin skin and with preexisting skin conditions may contribute significantly to the postsurgical result. Most publications and textbooks focus on the management of the osseocartilaginous framework, but the SSTE management is often not addressed in detail. However, nonsurgical treatments, such as skin preconditioning, topical steroid-injections, oral isotretinoin, and topical vitamin A derivatives, may provide strong benefits. In this article, we reviewed the literature to present a comprehensive review on the available surgical and nonsurgical approaches pre-, intra-, and postoperatively dealing with SSTE in rhinoplasty.

Respiratory syncytial virus in severe lower respiratory infections in previously healthy young Ethiopian infants.

BACKGROUND: Respiratory Syncytial Virus (RSV) is the commonest cause of acute lower respiratory infections (ALRI) in infants. However, the burden of RSV is unknown in Ethiopia. We aimed to determine the prevalence, seasonality and predictors of RSV infection in young infants with ALRI for the first time in Ethiopia. METHODS: We performed RSV immuno-chromatographic assay from nasopharyngeal swabs of infants, 29 days to 6 months of age. We included the first 10 eligible infants in each month from June 2018 to May 2019 admitted in a tertiary pediatric center. Clinical, laboratory and imaging data were also collected, and chi-square test and regression were used to assess associated factors with RSV infection. RESULTS: Among a total of 117 study children, 65% were male and mean age was 3 months. Bronchiolitis was the commonest diagnosis (49%). RSV was isolated from 26 subjects (22.2%) of all ALRI, 37% of bronchiolitis and 11% of pneumonia patients. Although RSV infection occurred year round, highest rate extended from June to November. No clinical or laboratory parameter predicted RSV infection and only rainy season (Adjusted Odds Ratio (AOR) 10.46 [95%. C.I. 1.95, 56.18]) was independent predictor of RSV infection. CONCLUSIONS: RSV was isolated in a fifth of young infants with severe ALRI, mostly in the rainy season. Diagnosis of RSV infection in our setting require specific tests as no clinical parameter predicted RSV infection. Since RSV caused less than a quarter of ALRI in our setting, the other causes should be looked for in future studies.

Optimization of the Soft Tissue Envelope of the Nose in Rhinoplasty Utilizing Fat Transfer Combined with Platelet-Rich Fibrin.

A thin or damaged skin soft tissue envelope may cause concerns in primary and secondary rhinoplasty. During postoperative healing, unpredictable scarring and contraction may occur and lead to significant aesthetic and trophic sequelae. Besides a meticulous surgical technique, there are no reliable techniques to prevent long-term skin damage and shrinkage. Fat transfer with addition of platelet-rich fibrin (PRF) harbors the possibility of local soft tissue regeneration and skin rejuvenation through growth factors and mesenchymal stem cells. It may also facilitate the creation of a thin fat layer on the dorsum to prevent shrink-wrap forces and conceal small irregularities. The goal is to provide evidence for the feasibility, durability, and beneficial effect of diced macrofat transfer bonded with PRF on the nasal dorsum. We present the technique of fat transfer conjugated with PRF as a nasal dorsal graft. Clinical endpoints were the prevention of trophic disturbances and atrophy at a 1-year postoperative follow-up. We present the skin mobility test as a clinical indicator of a healthy soft tissue envelope. The presented case series consists of 107 rhinoplasties. Fat was harvested in the umbilical or costal region. PRF was created by centrifugation of autologous whole blood samples. Macrofat was diced, cleaned, and bonded with PRF. The compound transplants were transferred to the nasal dorsum. There were no perioperative complications or wound-healing issues. Mean follow-up was 14 months. Clinical inspection showed good skin quality and no signs of shrinkage, marked scarring, or color changes with positive skin mobility test in all patients. Survival of fat was confirmed by ultrasonography and magnetic resonance imaging. Diced macrofat transfer in conjunction with PRF to the nasal dorsum is a feasible and safe method. A beneficial effect on the soft tissue envelope is demonstrated as well as the prevention of shrink-wrap forces.

Inter- and intra-tree variability of carbon and oxygen stable isotope ratios of modern pollen from nine European tree species.

Stable carbon and oxygen isotope ratios of raw pollen sampled from nine abundant tree species growing in natural habitats of central and northern Europe were investigated to understand the intra- and inter-specific variability of pollen-isotope values. All species yielded specific δ13Cpollen and δ18Opollen values and patterns, which can be ascribed to their physiology and habitat preferences. Broad-leaved trees flowering early in the year before leaf proliferation (Alnus glutinosa and Corylus avellana) exhibited on average 2.6‰ lower δ13Cpollen and 3.1‰ lower δ18Opollen values than broad-leaved and coniferous trees flowering during mid and late spring (Acer pseudoplatanus, Betula pendula, Carpinus betulus, Fagus sylvatica, Picea abies, Pinus sylvestris and Quercus robur). Mean species-specific δ13Cpollen values did not change markedly over time, whereas δ18Opollen values of two consecutive years were often statistically distinct. An intra-annual analysis of B. pendula and P. sylvestris pollen revealed increasing δ18Opollen values during the final weeks of pollen development. However, the δ13Cpollen values remained consistent throughout the pollen-maturation process. Detailed intra-individual analysis yielded circumferential and height-dependent variations within carbon and oxygen pollen-isotopes and the sampling position on a tree accounted for differences of up to 3.5‰ for δ13Cpollen and 2.1‰ for δ18Opollen. A comparison of isotope ranges from different geographic settings revealed gradients between maritime and continental as well as between high and low altitudinal study sites. The results of stepwise regression analysis demonstrated, that carbon and oxygen pollen-isotopes also reflect local non-climate environmental conditions. A detailed understanding of isotope patterns and ranges in modern pollen is necessary to enhance the accuracy of palaeoclimate investigations on δ13C and δ18O of fossil pollen. Furthermore, pollen-isotope values are species-specific and the analysis of species growing during different phenophases may be valuable for palaeoweather reconstructions of different seasons.

Diversification dynamics of freshwater bivalves (Unionidae: Parreysiinae: Coelaturini) indicate historic hydrographic connections throughout the East African Rift System.

Invertebrates are exceptionally diverse, but many are in decline because of anthropogenic changes to their habitat. This situation is particularly problematic for taxa that are not well monitored or taxonomically poorly understood, because the lack of knowledge hampers conservation. Despite their important functional role in freshwater ecosystems, African bivalves of the family Unionidae remain poorly studied compared to their highly threatened relatives in Europe, the U.S.A. and Canada. To resolve relationships and to study diversification dynamics in space and time, we performed time-calibrated phylogenetic studies and biogeographical modeling on the unionids from the East African Rift System and surroundings, including representatives of all currently recognized Afrotropical genera except for Brazzaea (and Unio from southern Africa). Our analyses indicate that all sampled Afrotropical unionids belong to the tribe Coelaturini (subfamily Parreysiinae), as does the genus Moncetia from Lake Tanganyika, which is currently attributed to the family Iridinidae. Colonization of Africa from Eurasia by Parreysiinae occurred ~17 Ma ago, and the subsequent diversification of Coelaturini in Africa continued at a steady pace, although net diversification decreased over time as more niches and ecoregions became occupied. Clades in Coelaturini largely reflect drainage basins, with the oldest lineages and highest regional diversity occurring in Lake Tanganyika, followed by the Congo Basin watershed in general. The species assemblage of Lake Tanganyika reflects multiple independent events of colonization and intralacustrine diversification since the Late Miocene or Early Pliocene. The clades of other regions, including that containing the species from Lake Malawi, are comparatively young. Biogeographical analyses indicate that the colonization history was mainly driven by cladogenesis in sympatry, whereas few anagenetic events contributed to the modern distribution of Coelaturini. Ancestral range estimations demonstrate that Coelaturini originated in the Victoria and/or Tanganyika ecoregions, and that the Congo Basin played an essential role in the colonization of Africa by Coelaturini.

Global Diversification Dynamics Since the Jurassic: Low Dispersal and Habitat-Dependent Evolution Explain Hotspots of Diversity and Shell Disparity in River Snails (Viviparidae).

The Viviparidae, commonly known as River Snails, is a dominant group of freshwater snails with a nearly worldwide distribution that reaches its highest taxonomic and morphological diversity in Southeast Asia. The rich fossil record is indicative of a probable Middle Jurassic origin on the Laurasian supercontinent where the group started to diversify during the Cretaceous. However, it remains uncertain when and how the biodiversity hotspot in Southeast Asia was formed. Here, we used a comprehensive genetic data set containing both mitochondrial and nuclear markers and comprising species representing 24 out of 28 genera from throughout the range of the family. To reconstruct the spatiotemporal evolution of viviparids on a global scale, we reconstructed a fossil-calibrated phylogeny. We further assessed the roles of cladogenetic and anagenetic events in range evolution. Finally, we reconstructed the evolution of shell features by estimating ancestral character states to assess whether the appearance of sculptured shell morphologies was driven by major habitat shifts. The molecular phylogeny supports the monophyly of the three subfamilies, the Bellamyinae, Lioplacinae, and Viviparinae, but challenges the currently accepted genus-level classification in several cases. The almost global distribution of River Snails has been influenced both by comparatively ancient vicariance and more recent founder events. In Southeast Asia, Miocene dispersal was a main factor in shaping the modern species distributions. A recurrent theme across different viviparid taxa is that many species living in lentic waters exhibit sculptured shells, whereas only one strongly sculptured species is known from lotic environments. We show that such shell sculpture is habitat-dependent and indeed evolved several times independently in lentic River Snails. Considerably high transition rates between shell types in lentic habitats probably caused the co-occurrence of morphologically distinct shell types in several lakes. In contrast, directional evolution toward smooth shells in lotic habitats, as identified in the present analyses, explains why sculptured shells are rarely found in these habitats. However, the specific factors that promoted changes in shell morphology require further work. [biogeographical analyses; fossil-calibrated phylogeny; fossil-constrained analyses; Southeast Asia; stochastic character mapping.].

Retropharyngeal Tuberculous Abscess: A Rare Cause of Upper Airway Obstruction and Obstructive Sleep Apnea in Children: A Case Report.

Retropharyngeal tuberculous abscess (RPTBA) is a rare manifestation of tuberculosis (TB) even in high TB burden areas. It rarely manifests as a cause of upper airway obstruction and obstructive sleep apnea (OSA) in children with few case reports in the literature. We report a 22 months old toddler who presented with upper airway obstruction and OSA and was diagnosed with RPTBA. The child recovered completely and growing normally after intra-oral aspiration and 6 months of anti-tuberculosis treatment.

Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas.

Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (δ18O, δ13C) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (δ18Osw) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (δ18Osw), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low δ18Osw) versus Mediterranean (high δ18Osw) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front.

Systematic Review of Quality-of-Life Measurement After Aesthetic Rhinoplasty.

INTRODUCTION: The assessment of outcomes in aesthetic rhinoplasty is highly relevant because patient satisfaction and improved health-related quality of life (QoL) are the predominant factors in determining success. The patient-reported outcome measures (PROMs) employed in rhinoplasty research studies are remarkably diverse, thus yielding difficulties with data analysis. The aim of this article is to provide a comprehensive review of the literature to reveal the relevance of the QoL assessment for rhinosurgeons. METHODS: A systematic literature search with the terms "Rhinoplasty" and "Quality of Life" was conducted using PubMed/MEDLINE, Google Scholar and Cochrane databases. Primarily, all publications related to QoL following aesthetic rhinoplasty between 2002 and 2017 were identified. As a secondary selection, we focused on articles with a prospective study design, a significant cohort size (at least 50 patients) and a follow-up period of at least 6 months after aesthetic rhinoplasty. RESULTS: A total of 62 PROM studies assessing QoL following aesthetic rhinoplasties were obtained. We ascertained an increasing publication rate of QoL articles over the last 15 years. Only 17 studies satisfied comprehensive inclusion criteria of a high qualitative study selection. The Rhinoplasty Outcome Evaluation was the most frequently used QoL questionnaire of the secondary selection (70.6%). The total number of 16 various questionnaires exhibit high heterogeneity. CONCLUSION: Our data strengthen the increasing importance of the assessment of QoL after rhinoplasty. Despite a lack of reliable publications with considerable heterogeneity and large variability in outcomes, functional-aesthetic rhinoplasty leads to a significant improvement of patient's health-related QoL. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Cartilage Scales Embedded in Fibrin Gel.

Multiple techniques have been described for dorsal nasal augmentation in rhinoplasty. In this article, we review common surgical techniques for raising the dorsum or eliminating dorsal irregularities, by highlighting inherent advantages and disadvantages of each method. Within the past few years, the use of diced cartilage grafts has become the workhorse in this field of interest. To overcome drawbacks of methods based on diced cartilage, we present a new concept for autologous augmentation, using regenerative medicine protocols. A mix of cartilage scales with cartilage pâté was embedded in platelet-rich fibrin (PRF). Since December 2015, a total of 48 patients were treated with this technique. Based on our preliminary results, cartilage scales in PRF appear to be a promising and reliable alternative to existing procedures for dorsal nasal augmentation.

Options for Middle Vault and Dorsum Restoration after Hump Removal in Primary Rhinoplasty.

Prevention of unfavorable sequelae following humpectomy in reduction rhinoplasty by restoration of the middle nasal vault complex today has become imperative in the majority of patients with perhaps the exception of small humps. In general, the techniques used for preservation and reconstruction of these important anatomical structures can be divided into two main categories: spreader graft and spreader flap techniques. Oversimplified spreader graft techniques require donor cartilage, whereas spreader flap techniques use the excess height of the medial portion of the upper lateral cartilages in patients with a cartilaginous hump. In principle, both donor cartilage and preserved upper lateral cartilages usually are positioned along both sides of the dorsal septum to provide natural and harmonious contours as well as to avoid functional impairment (valve collapse). However, the considerable number of publications on this topic attests to existing downsides of both surgical principles. To overcome these shortcomings, we illustrate additional modifications in the application of spreader grafts as well as spreader flaps. However, the main goal of this article is to provide an algorithm helping to decide which technique is best suited to meet the requirements of each individual patient.

Dome Reconstruction in a Rare Case of Alar Cartilage Agenesis of the Middle and Lateral Crura.

UNLABELLED: Congenital deformities of the nasal cartilage are extremely rare. Often, they remain undiscovered until an open approach is completed during rhinoplasty. We present a case of unilateral congenital agenesis of the middle and lateral crura of the alar cartilage. A new concept for dome reconstruction using conchal cartilage is introduced. Additionally, current concepts of embryology are summarized, which will help understanding the pathophysiology of such rare deformities. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Ecophenotypic plasticity leads to extraordinary gastropod shells found on the "Roof of the World".

The often extraordinary shell forms and shapes of gastropods found in palaeolakes, such as the highly diverse Gyraulus fauna of the famous Steinheim Basin, have been puzzling evolutionary biologists for centuries, and there is an ongoing debate whether these aberrant shell forms are indicative of true species (or subspecies) or ecophenotypic morphs. Interestingly, one of the Steinheim Gyraulus morphs - a corkscrew-like open-coiled shell - has a recent analogue in the Lake Bangong drainage system on the western Tibetan Plateau. Therefore, a combination of morphological, molecular, palaeolimnological, and ecological analyses was used in this study to assess whether the extraordinary shell shape in Gyraulus sp. from this drainage system represents a (young) ecophenotypic phenomenon or if it has been genetically fixed over an extended period of time. Our morphological, ecological, and palaeolimnological data suggest that the corkscrew-like specimens remain restricted to a small pond near Lake Bangong with an elevated pH value and that the colonization may have occurred recently. The phylogenetic reconstruction based on two gene fragments shows that these nonplanispiral specimens cluster within the previous described Tibetan Plateau Gyraulus clade N2. A network analysis indicates that some haplotypes are even shared by planispiral and nonplanispiral specimens. Given the ephemerality of the phenomenon, the compact network patterns inferred, the likely young phylogenetic age of the aberrant Gyraulus shells studied, and the ecological peculiarities of the study site, we suggest that the evolution of the aberrant shell forms on the Tibetan Plateau could likely be considered as a rapid ecophenotypic response, possibly induced by ecological stress. This finding may thus have implications for the ongoing debate about the processes that have caused the extraordinary shell diversity in palaeolakes such as the Steinheim Basin.

Disjunct distributions of freshwater snails testify to a central role of the Congo system in shaping biogeographical patterns in Africa.

BACKGROUND: The formation of the East African Rift System has decisively influenced the distribution and evolution of tropical Africa's biota by altering climate conditions, by creating basins for large long-lived lakes, and by affecting the catchment and drainage directions of river systems. However, it remains unclear how rifting affected the biogeographical patterns of freshwater biota through time on a continental scale, which is further complicated by the scarcity of molecular data from the largest African river system, the Congo. RESULTS: We study these biogeographical patterns using a fossil-calibrated multi-locus phylogeny of the gastropod family Viviparidae. This group allows reconstructing drainage patterns exceptionally well because it disperses very poorly in the absence of existing freshwater connections. Our phylogeny covers localities from major drainage basins of tropical Africa and reveals highly disjunct sister-group relationships between (a) the endemic viviparids of Lake Malawi and populations from the Middle Congo as well as between (b) the Victoria region and the Okavango/Upper Zambezi area. CONCLUSIONS: The current study testifies to repeated disruptions of the distribution of the Viviparidae during the formation of the East African Rift System, and to a central role of the Congo River system for the distribution of the continent's freshwater fauna during the late Cenozoic. By integrating our results with previous findings on palaeohydrographical connections, we provide a spatially and temporarily explicit model of historical freshwater biogeography in tropical Africa. Finally, we review similarities and differences in patterns of vertebrate and invertebrate dispersal. Amongst others we argue that the closest relatives of present day viviparids in Lake Malawi are living in the Middle Congo River, thus shedding new light on the origin of the endemic fauna of this rift lake.