The Future of Forecasting Competitions: Design Attributes and Principles

Forecasting competitions are the equivalent of laboratory experimentation widely used in physical and life sciences. They provide useful, objective information to improve the theory and practice of forecasting, advancing the field, expanding its usage, and enhancing its value to decision and policymakers. We describe 10 design attributes to be considered when organizing forecasting competitions, taking into account trade-offs between optimal choices and practical concerns, such as costs, as well as the time and effort required to participate in them. Consequently, we map all major past competitions in respect to their design attributes, identifying similarities and differences between them, as well as design gaps, and making suggestions about the principles to be included in future competitions, putting a particular emphasis on learning as much as possible from their implementation in order to help improve forecasting accuracy and uncertainty. We discuss that the task of forecasting often presents a multitude of challenges that can be difficult to capture in a single forecasting contest. To assess the caliber of a forecaster, we, therefore, propose that organizers of future competitions consider a multicontest approach. We suggest the idea of a forecasting-“athlon” in which different challenges of varying characteristics take place.

Pengaruh Pemberian Ekstrak Stichopus hermanii Semper, 1868 (Stichopodidae, Holothuroidea) terhadap Jumlah Total Hemosit Litopenaeus vannamei Boone, 1931 (Penaeidae, Crustacea)

Peningkatan imunitas udang vaname dengan menggunakan imnostimulator merupakan salah satu upaya untuk mencegah kegagalan panen pada budidaya udang vaname. Ekstrak teripang emas memiliki senyawa yang berperan sebagai peningkat imun. Beberapa senyawa yang terkandung pada teripang emas yaitu saponin dan steroid. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh pemberian ekstrak teripang emas terhadap jumlah total hemosit Litopenaeus vannamei dan konsentrasi ekstrak teripang emas yang paling tepat untuk meningkatkan jumlah total hemosit udang vaname. Metode yang digunakan adalah metode eksperimen laboratoris dengan perlakuan konsentrasi ekstrak teripang emas yang ditambahkann pada pakan udang komersil yaitu 0 ppm; 40 ppm; 80 ppm; 120 ppm. Hasil penelitian jumlah total hemosit udang vaname terjadi peningkatan akibat pemberian ekstrak teripang emas dibandingkan kontrol. Peningkatan tersebut terlihat pada jumlah total hemosit udang vaname yang diberi ekstrak teripang emas dengan konsentrasi 40 dan 120 ppm pada hari ke-8. Pemberian ekstrak teripang emas dengan konsentrasi 120 ppm memberikan hasil terbaik yaitu jumlah total hemosit sebanyak 1,18x106 sel/mL, dan untuk kelangsungan hidup udang vaname yang diberikan ekstrak teripang emas dan kontrol memiliki persentase sebesar 100%. Kesimpulannya adalah pemberian ekstrak teripang emas berpengaruh terhadap jumlah hemosit udang vaname. Increased immunity of vaname shrimp by using imnostimulator is one of the efforts to prevent crop failure in the cultivation of vaname shrimp. gold sea cucumber extract has a compound that acts as an immune enhancer. Some of the compounds contained in Stichopus hermanii are saponins and steroids. The purpose of this study was to determine the effect of gold sea cucumber extract on the total amount of vaname shrimp haemocyte and the most appropriate concentration of golden sea cucumber extract to increase the total amount of vaname shrimp haemocyte. The method used was a method of laboratory experimentation with the treatment of the concentration of Stichopus hermanii extract added to commercial shrimp feed that is 0 ppm; 40 ppm; 80 ppm; 120 ppm. The results of the study the total amount of shrimp haemocyte Litopenaeus vananamei increased due to administration of Stichopus hermanii extract compared to control. The increase was seen in the total amount of vaname shrimp haemocyte given gold sea cucumber extract with concentrations of 40 and 120 ppm on day 8. Administration of gold sea cucumber extract with a concentration of 120 ppm gives the best result that is the total amount of haemocyte as much as 1.18x106 cells / mL, and for the survival of Litopenaeus vannamei given extract gold sea cucumber and control has a percentage of 100%. The conclusion is that the administration of gold sea cucumber extract affects the amount of haemocyte shrimp vaname.

Effect of Longitudinal Fastener Stiffness on Fastening System Loading - Initial Findings

Over the past 20 years, there have been at least 10 derailments due to spike fatigue failures in North America. Researchers believe that fatigue failure is caused by a combination of lateral and longitudinal spike loading. The literature indicates the vertical load and fastener friction must be considered when estimating failure locations. Though the in-track vertical, lateral, and longitudinal fastener forces have been quantified at a location that has experienced spike failures, there is a need to account for additional fasteners and track locations. Fastening systems can affect track stiffness, thus, laboratory experimentation was performed to quantify stiffness of multiple fastening systems. This data was input into an analytical model which quantified the effect of stiffness on longitudinal fastener loading. The data indicate there is significant variance in fastening system stiffness within, and between, systems. However, this variation in fastener stiffness has a reduced effect on the load transferred to the fastening system. More work is needed to validate this in the lab or field given variability within a system could lead to stress concentrations that are not fully captured using the current idealized analytical method.

Efficacy of Face Masks Used in Uganda: A Laboratory-Based Inquiry during the COVID-19 Pandemic

With shortages of face masks being reported worldwide, it is critical to consider alternatives to commercially manufactured face masks. This study aimed to test and compare the efficacy of various makes of locally made or homemade cloth face masks obtained from face-mask vendors in Kampala, Uganda, during the COVID-19 pandemic. The testing was performed to assess the bacterial filtration efficiency (BFE), breathability, distance-dependent fitness, and reusability of the locally made or homemade cloth face masks, while considering the most commonly used non-published face-mask decontamination approaches in Uganda. During laboratory experimentation, modified protocols from various face-mask testing organizations were adopted. Ten different face-mask types were experimented upon; each face-mask type was tested four times for every single test, except for the decontamination protocols involving washing where KN95 and surgical face masks were not included. Among the locally made or homemade cloth face masks, the double-layered cloth face masks (described as F) had better BFE and distance-dependent fitness characteristics, they could be reused, and had good breathability, than the other locally made or homemade cloth face masks. Despite these good qualities, the certainty of these face masks protecting wearers against COVID-19 remains subject to viral filtration efficiency testing.

The Hydrodynamics of Jellyfish Swimming

Jellyfish have provided insight into important components of animal propulsion, such as suction thrust, passive energy recapture, vortex wall effects, and the rotational mechanics of turning. These traits are critically important to jellyfish because they must propel themselves despite severe limitations on force production imposed by rudimentary cnidarian muscular structures. Consequently, jellyfish swimming can occur only by careful orchestration of fluid interactions. Yet these mechanics may be more broadly instructive because they also characterize processes shared with other animal swimmers, whose structural and neurological complexity can obscure these interactions. In comparison with other animal models, the structural simplicity, comparative energetic efficiency, and ease of use in laboratory experimentation allow jellyfish to serve as favorable test subjects for exploration of the hydrodynamic bases of animal propulsion. These same attributes also make jellyfish valuable models for insight into biomimetic or bioinspired engineeringof swimming vehicles. Here, we review advances in understanding of propulsive mechanics derived from jellyfish models as a pathway toward the application of animal mechanics to vehicle designs.