The evolution of acoustic identity signals in birds

In this dissertation I present several novel findings on the evolution of acoustic identity traits in birds, with a special focus on parent-offspring communication. I present novel insights on how vocalizations are influenced by condition, environment and genes, and which acoustic parameters are used to form unique identity signatures. Furthermore, I provide first experimental evidence for the role of acoustic similarity for recognition errors in birds, supporting the importance of negative-frequency dependent selection for the evolution and spread of individual signatures

The effect of hunger on the acoustic individuality in begging calls of a colonially breeding weaver bird

<p>Abstract</p> <p>Background</p> <p>In colonially breeding birds, the ability to discriminate between individuals is often essential. During post-fledging care, parents have to recognize their own offspring among many other unrelated chicks in the breeding colony. It is well known that fledglings and food-provisioning parents of many bird species use contact calls to convey their identity. These calls are also often used as hunger-related signals of need in young birds. Here, we investigate how such calls incorporate signals of need and at the same time act as reliable indicators of each chick's identity.</p> <p>Results</p> <p>In a field study, we experimentally manipulated the hunger level of colonially breeding Jackson's golden-backed weaver (<it>Ploceus jacksoni</it>) nestlings close to fledging and investigated its effects on acoustic call parameters. Some acoustic parameters that were related to the time-frequency pattern showed high individuality and were largely unaffected by a nestling's state of hunger. However, the majority of call parameters were significantly affected by hunger. Interestingly, most of these acoustic parameters showed both consistent changes with hunger and high between-individual differences, i.e. potential for individual recognition.</p> <p>Conclusion</p> <p>The results indicate that individual recognition processes can be based on static, hunger-independent call parameters, but also on dynamic hunger-related parameters that show high individuality. Furthermore, these signal properties suggest that the assessment of signals of need can be improved if the signal value is referenced to a chick's vocal spectrum.</p

Old Crops in a New World: Bringing Andean Tuber Crops to the Pacific Northwest

Though currently relatively unknown outside Latin America, Andean root and tuber crops are rapidly gaining interest elsewhere. Tubers are a major food and important sources of nutrition in South America and have potential in countries outside their center of origin. We conducted a two-part study on oca (Oxalis tuberosa), mashua (Tropaeolum tuberosum), ulluco (Ullucus tuberosus), and mauka (Mirabilis expansa) planting and harvesting over a two-year period to study the feasibility of cultivation and use in the Pacific Northwest (PNW). We also observed crops and interviewed key informants in Peru and Ecuador, and in the PNW concerning cultivation, loss of genetic variation and preservation efforts, and usage and perceptions. In the PNW, we also investigated commercial potential and general public knowledge and interest. Our findings suggest that these plant species will grow and produce tubers in the PNW and can also produce viable seed, which is extremely important for breeding varieties better adapted to the PNW and other similar growing regions. The loss of genetic diversity of oca, mashua, and mauka observed in Peru and Ecuador could potentially be counteracted by their cultivation and genetic improvement in the PNW, where there is an increase in cultivation, sales, and interest. Key Words: oca; mashua; ulluco; mauka; Orego

Control of mitochondrial pH by uncoupling protein 4 in astrocytes promotes neuronal survival.

Brain activity is energetically costly and requires a steady and highly regulated flow of energy equivalents between neural cells. It is believed that a substantial share of cerebral glucose, the major source of energy of the brain, will preferentially be metabolized in astrocytes via aerobic glycolysis. The aim of this study was to evaluate whether uncoupling proteins (UCPs), located in the inner membrane of mitochondria, play a role in setting up the metabolic response pattern of astrocytes. UCPs are believed to mediate the transmembrane transfer of protons, resulting in the uncoupling of oxidative phosphorylation from ATP production. UCPs are therefore potentially important regulators of energy fluxes. The main UCP isoforms expressed in the brain are UCP2, UCP4, and UCP5. We examined in particular the role of UCP4 in neuron-astrocyte metabolic coupling and measured a range of functional metabolic parameters including mitochondrial electrical potential and pH, reactive oxygen species production, NAD/NADH ratio, ATP/ADP ratio, CO2 and lactate production, and oxygen consumption rate. In brief, we found that UCP4 regulates the intramitochondrial pH of astrocytes, which acidifies as a consequence of glutamate uptake, with the main consequence of reducing efficiency of mitochondrial ATP production. The diminished ATP production is effectively compensated by enhancement of glycolysis. This nonoxidative production of energy is not associated with deleterious H2O2 production. We show that astrocytes expressing more UCP4 produced more lactate, which is used as an energy source by neurons, and had the ability to enhance neuronal survival

Incidence of left atrial abnormalities under treatment with dabigatran, rivaroxaban, and vitamin K antagonists

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran or rivaroxaban are alternatives to vitamin K antagonists (VKAs) for prevention of stroke and systemic embolism in patients with atrial fibrillation (AF) and atrial flutter (AFL). Incidences of risk factors for left atrium (LA) and left atrial appendage (LAA) thrombus formation, such as dense spontaneous echo contrast (SEC), low LAA velocity (LAAV) <20 cm/s under treatment with dabigatran and rivaroxaban in comparison with VKAs are unknown. METHODS: We studied 306 patients with AF (94 %) and AFL (6 %) undergoing transesophageal echocardiography. Patients received VKAs (n = 138), dabigatran (n = 68), or rivaroxaban (n = 100) for at least 3 weeks prior to investigation. Time in therapeutic range was 67 % for VKA. Mean CHADS(2) score and CHA(2)DS(2)-VASc score were 1.3 and 2.5, respectively. Left atrial abnormality was defined as either dense SEC, low LAAV <20 cm/s, or thrombus. RESULTS: Any LA abnormality occurred in 9, 3, and 5 % of patients receiving VKA, dabigatran, and rivaroxaban, respectively. The most frequent abnormality was LAA thrombus (VKA: 4 %, dabigatran: 0 %, rivaroxaban: 2 %) and low LAAV of less than 20 cm/s (VKA: 4 %, dabigatran: 1 %, rivaroxaban: 1 %), followed by dense SEC (VKA: 2 %, dabigatran: 1 %, rivaroxaban: 2 %). Results of uni- and multivariate analyses revealed a numerically lower but not significantly different frequency of any LA abnormality under dabigatran (OR 0.4, 95 % Cl 0.08 − 1.88, p = 0.25) and rivaroxaban (OR 0.65, 95 % Cl 0.22 − 1.98, p = 0.45) compared to VKA. CONCLUSION: With respect to the incidence of LA abnormalities, dabigatran and rivaroxaban are not inferior to VKA

Overview of BirdCLEF 2023: Automated bird species identification in Eastern Africa

The BirdCLEF 2023 challenge focused on bird species classification in a dataset of Kenyan soundscape recordings. Kenya is home to over 1,000 species of birds, covering a wide range of ecosystems, from the savannahs of the Maasai Mara to the Kakamega rainforest, and even alpine regions on Kilimanjaro and Mount Kenya. Tracking this vast number of species with ML can be challenging, especially with minimal training data available for many species. This year the competition switched back to threshold-free evaluation metric, and introduced a two-hour time limit on inference to ensure the practical usability of models

1-(5-Carboxy­pent­yl)-2,3,3-trimethyl-3H-indol-1-ium bromide monohydrate

In the title compound, C17H24NO2 +·Br−·H2O, the pentyl group chain in the cation extends nearly perpendicular [N—C—C—C = −64.4 (3)°] to the mean plane of the indole ring with the carboxyl end group twisted such that the dihedral angle between the mean planes of the indole and carb­oxy groups measures 43.2 (4)°. Both ions in the salt form inter­molecular hydrogen bonds (O—H⋯Br and O—H⋯O) with the water mol­ecule. As a result of the Br⋯H—O—H⋯Br inter­actions, a zigzag chain is formed in the c-axis direction. The crystal packing is influenced by the collective action of the O—H⋯O and O—H⋯Br inter­molecular inter­actions as well as π–π stacking inter­molecular inter­actions between adjacent benzyl rings of the indole group [centroid–centroid distance = 3.721 (13) Å] and inter­molecular C—H⋯π inter­actions between a methyl hydrogen and the benzyl ring of the indole group. The O—H⋯Br inter­actions form a distorted tetra­hedral array about the central Br atom. A MOPAC AM1 calculation provides support to these observations

Do Zebra Finch Parents Fail to Recognise Their Own Offspring?

Individual recognition systems require the sender to be individually distinctive and the receiver to be able to perceive differences between individuals and react accordingly. Many studies have demonstrated that acoustic signals of almost any species contain individualized information. However, fewer studies have tested experimentally if those signals are used for individual recognition by potential receivers. While laboratory studies using zebra finches have shown that fledglings recognize their parents by their “distance call”, mutual recognition using the same call type has not been demonstrated yet. In a laboratory study with zebra finches, we first quantified between-individual acoustic variation in distance calls of fledglings. In a second step, we tested recognition of fledgling calls by parents using playback experiments. With a discriminant function analysis, we show that individuals are highly distinctive and most measured parameters show very high potential to encode for individuality. The response pattern of zebra finch parents shows that they do react to calls of fledglings, however they do not distinguish between own and unfamiliar offspring, despite individual distinctiveness. This finding is interesting in light of the observation of a high percentage of misdirected feedings in our communal breeding aviaries. Our results demonstrate the importance of adopting a receiver's perspective and suggest that variation in fledgling contact calls might not be used in individual recognition of offspring

Ternary structure of Plasmodium vivaxN-myristoyltransferase with myristoyl-CoA and inhibitor IMP-0001173

Abstract Plasmodium vivax is a major cause of malaria, which poses an increased health burden on approximately one third of the world's population due to climate change. Primaquine, the preferred treatment for P. vivax malaria, is contraindicated in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, a common genetic cause of hemolytic anemia, that affects ∼2.5% of the world's population and ∼8% of the population in areas of the world where P. vivax malaria is endemic. The Seattle Structural Genomics Center for Infectious Disease (SSGCID) conducted a structure–function analysis of P. vivax N-myristoyltransferase (PvNMT) as part of efforts to develop alternative malaria drugs. PvNMT catalyzes the attachment of myristate to the N-terminal glycine of many proteins, and this critical post-translational modification is required for the survival of P. vivax. The first step is the formation of a PvNMT–myristoyl–CoA binary complex that can bind to peptides. Understanding how inhibitors prevent protein binding will facilitate the development of PvNMT as a viable drug target. NMTs are secreted in all life stages of malarial parasites, making them attractive targets, unlike current antimalarials that are only effective during the plasmodial erythrocytic stages. The 2.3 Å resolution crystal structure of the ternary complex of PvNMT with myristoyl-CoA and a novel inhibitor is reported. One asymmetric unit contains two monomers. The structure reveals notable differences between the PvNMT and human enzymes and similarities to other plasmodial NMTs that can be exploited to develop new antimalarials.Abstract Plasmodium vivax is a major cause of malaria, which poses an increased health burden on approximately one third of the world's population due to climate change. Primaquine, the preferred treatment for P. vivax malaria, is contraindicated in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, a common genetic cause of hemolytic anemia, that affects ∼2.5% of the world's population and ∼8% of the population in areas of the world where P. vivax malaria is endemic. The Seattle Structural Genomics Center for Infectious Disease (SSGCID) conducted a structure–function analysis of P. vivax N-myristoyltransferase (PvNMT) as part of efforts to develop alternative malaria drugs. PvNMT catalyzes the attachment of myristate to the N-terminal glycine of many proteins, and this critical post-translational modification is required for the survival of P. vivax. The first step is the formation of a PvNMT–myristoyl–CoA binary complex that can bind to peptides. Understanding how inhibitors prevent protein binding will facilitate the development of PvNMT as a viable drug target. NMTs are secreted in all life stages of malarial parasites, making them attractive targets, unlike current antimalarials that are only effective during the plasmodial erythrocytic stages. The 2.3 Å resolution crystal structure of the ternary complex of PvNMT with myristoyl-CoA and a novel inhibitor is reported. One asymmetric unit contains two monomers. The structure reveals notable differences between the PvNMT and human enzymes and similarities to other plasmodial NMTs that can be exploited to develop new antimalarials