TEXT

The ongoing COVID-19 crisis has had an especially pernicious impact on the energy market, as worldwide lockdown measures and the ensuing war between oil superpowers Russia and OPEC have led to an unprecedented drop in oil prices in April 2020. Energy producers are now struggling to recover from the shocks in supply and demand that have destabilized the market. This underlies a need for firms to anticipate future price volatility in planning out their strategies. The recent developments in energy pricing motivate our study of commodity markets modeled as dynamic Cournot games, where the market demand and producers' inventories are governed by stochastic processes. We introduce the game theoretic framework of $N$-player continuous-time Cournot games, where firms choose production quantities at each time period to maximize their individual profit. The production side of the market consists of both fossil fuel-based (i.e. exhaustible) and renewable (inexhaustible) energy producers who maximize their value functions characterized by a system of nonlinear Hamilton-Jacobi-Bellman (HJB) partial differential equations. The unique market price of this economic game is given by a constant prudence price function, where the prudence coefficient takes values in $[0, 2)$. We characterize the market price volatility for different oligopoly patterns, both analytically and through numerical simulation. This allows us to compare the price volatility curves for different values of the constant prudence coefficient, which reflects the changes in market structure due to consumers' varying willingness to invest in energy services in the face of market uncertainty

Dynamic Cournot Games of Energy Production under Constant Prudence Price Functions

The ongoing COVID-19 crisis has had an especially pernicious impact on the energy market, as worldwide lockdown measures and the ensuing war between oil superpowers Russia and OPEC have led to an unprecedented drop in oil prices in April 2020. Energy producers are now struggling to recover from the shocks in supply and demand that have destabilized the market. This underlies a need for firms to anticipate future price volatility in planning out their strategies. The recent developments in energy pricing motivate our study of commodity markets modeled as dynamic Cournot games, where the market demand and producers' inventories are governed by stochastic processes. We introduce the game theoretic framework of $N$-player continuous-time Cournot games, where firms choose production quantities at each time period to maximize their individual profit. The production side of the market consists of both fossil fuel-based (i.e. exhaustible) and renewable (inexhaustible) energy producers who maximize their value functions characterized by a system of nonlinear Hamilton-Jacobi-Bellman (HJB) partial differential equations. The unique market price of this economic game is given by a constant prudence price function, where the prudence coefficient takes values in $[0, 2)$. We characterize the market price volatility for different oligopoly patterns, both analytically and through numerical simulation. This allows us to compare the price volatility curves for different values of the constant prudence coefficient, which reflects the changes in market structure due to consumers' varying willingness to invest in energy services in the face of market uncertainty

Trouessartia dicruri Constantinescu, sp. n.

<i>Trouessartia dicruri</i> Constantinescu sp. n. <p>(Figs. 7–12)</p> <p> <b>Description.</b> MALE (Figs. 7, 8, 9 A–E; holotype and 5 paratypes): Length of idiosoma from anterior end to bases of setae <i>h3</i> 415 (420–450), greatest width at level of humeral shields 210 (210–240). Length of hysterosoma from sejugal furrow to bases of setae <i>h3</i> 270 (275–290). Prodorsal shield: length along midline 130 (135–150), greatest width in posterior part 140 (135–150), lateral margins not fused with scapular shields, with antero-lateral extensions almost extending to bases of epimerites Ia between legs I and II, surface without ornamentation (Fig. 7). Internal scapular setae <i>si</i> filiform, 24 (24–30) long, separated by 56 (50–60); external scapular setae <i>se</i> situated on prodorsal shield, distance <i>se–se</i> 96 (92–108). Setae <i>ve</i> represented by alveoli. Setae <i>c2</i> on humeral shield, spiculiform, 44 (45–51) long. Setae <i>c3</i> narrowly lanceolate, with acute apex, 20 (20–24) long. Dorsal hysterosoma with prohysteronotal shield and lobar shield connected, delimited from each other by lateral incisions immediately posterior to setae <i>e2</i> and small desclerotized median area of triangular form. Prohysteronotal shield length 175 (175–185), width at anterior margin 155 (150–160), lateral margins incised at level of trochanters III, bottom of this incisions with C-shaped dark sclerotization, dorsal hysterosomal apertures (DHA) absent. Dorsal setae <i>d1</i>, <i>d2</i> present, minute. Length of lobar shield excluding lamellae 90 (88–94). Apical parts of opisthosomal lobes approximate, separated by narrow parallel-sided terminal cleft, length of this cleft from anterior end to apices of lamellae 42 (39–45), width in anterior part 5 (5–6). Lamella shaped as a parallelogram, attenuate apically, margins smooth, length from bases of setae <i>h3</i> to apices 30 (28–30). Setae <i>h1</i> anterior to setae <i>h2</i>. Distance between dorsal setae: <i>c2-d2</i> 84 (84–96), <i>d2- e2</i> 90 (91–100), <i>e2-h2</i> 76 (76–80), <i>h2-h3</i> 20 (18–20), <i>h2-h2</i> 30 (32–35), <i>h3-h3</i> 30 (28– 32), <i>d1-d2</i> 34 (30–40), <i>e1- e2</i> 44 (44–48). Epimerites I free. Rudimentary sclerites rEpIIa present, small, roughly ovoid. Genital apparatus situated between levels of trochanters III and IV, length 50 (48–51), greatest width 38 (36–46) (Fig. 8). Epiandrum present, small, setae <i>g</i> long and contiguous at bases (Fig. 9 E). Posterior genital papillae more distant from midline than anterior ones, postgenital plaque present. Adanal apodemes heavily sclerotized, with narrow lateral membrane, without apophyses. Translobar apodeme present. Adanal shields well developed and shaped as inverted comma, situated antero-lateral to anal suckers, bearing setae <i>ps3</i>. Anal suckers 12 (12–14) in diameter. Anterior ends of epimerites IV not reaching level of setae <i>4b</i>, epimerites IVa present, anterior ends not touching level of setae <i>4a.</i> Setae <i>4b</i> situated anterior to level of setae <i>3a</i>, setae <i>g</i> situated posterior to level of setae <i>4a</i>. Distance between ventral setae: <i>4b-3a</i> 38 (37–45), <i>4b-g</i> 80 (84–93), <i>g-ps3</i> 66 (68–72), <i>ps3-h3</i> 82 (78–84). Setae <i>sR</i> of trochanters III lanceolate, with acute apex, 13 (12–16) long. Tarsus IV 44 (42–48) long, modified setae <i>d</i> barrel-shaped, with discoid cap, situated at midlevel of segment, setae <i>e</i> hemispheroid, without cap, situated apically (Fig. 9 D). Legs IV with ambulacral disc extending up to level of setae <i>h3</i>.</p> <p> FEMALE (Figs. 10, 11, 12 A–E; 4 paratypes): Length of idiosoma from anterior end to apices of lamellar lobar processes 500–530, greatest width 220–235. Length of hysterosoma from sejugal furrow to apices of lamellar lobar processes 345–350. Prodorsal shield shaped as in male, 145–160 in length, 135–155 in width, surface without ornamentation. Setae <i>si</i> thin, filiform, 24–26 long, separated by 60–64, external scapular setae <i>se</i> situated on prodorsal shield, separated by 99–105. Setae <i>c2</i> on humeral shields, spiculiform, 44–50 long. Setae <i>c3</i> narrowly lanceolate, with acute apex, 22–24 in length. Hysteronotal shield length from anterior margin to bases of setae <i>h3</i> 300–310, width at anterior margin 160–170, lateral margins incised at level of trochanters III, bottom of this incisions with C-shaped dark sclerotisation, dorsal hysterosomal apertures (DHA) absent, posterior part with big ovate lacunae, ornamentation does not exceed level of <i>d2</i> setae. Dorsal setae <i>d1</i>, <i>d2</i> present, minute. Setae <i>h1</i> lanceolate, with acute apex, 16–18 long, situated antero-mesal to bases of setae <i>h2</i>, 20–24 from each lateral margin of hysteronotal shield. Setae <i>ps1</i> positioned on mesal margin of lobe, closer to base of <i>h2</i> setae. Distance from bases of setae <i>h3</i> to membranous apices of lobes 30–33. Setae <i>f2</i> absent. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft together with supranal concavity 130–140, width of cleft at level of setae <i>h3</i> 52–66. Interlobar membrane occupying anterior 1/5 of terminal cleft, distance from its anterior margin to membranous lobar apices 105–115. External copulatory tube present, 8–12 long, protruding from free margin of interlobar membrane. Spermatheca with primary spermaduct thickened in distal part, length of secondary spermaducts 30–34 (Fig. 12 E). Distance between dorsal setae: <i>c2-d2</i> 85–90, <i>d2- e2</i> 80–90, <i>e2-h2</i> 62–72, <i>h2-h3</i> 72– 80, <i>h2-h2</i> 82–90, <i>h3-h3</i> 64–72, <i>d1-d2</i> 35–37, <i>e1- e2</i> 38–46, <i>h1-h 2</i> 24–26, <i>h1-h1</i> 50–54, <i>ps1-h3</i> 45–54. Epimerites I free. Epigynum 30–34 in length, 78–86 in width (Fig. 11). Epimerites IVa present, wide and short. Setae <i>sR</i> of trochanters III lanceolate, with acute apex, 13–16 long. Legs IV with ambulacral disc extending to midlevel between setae <i>h2</i> and <i>h3</i>.</p> <p> <b>Type material.</b> Male holotype (ANA 429), 5 male paratypes (ANA 430, ANA 431, ANA 432, ANA 433, ANA 434), and 4 female paratypes (ANA 424, ANA 425, ANA 426, ANA 427) ex <i>Dicrurus aeneus</i> (Vieillot) (Passeriformes: Dicruridae), <b>INDIA</b>: Meghalaya, Jaintia Hills, Shnongrim, 25°21'12.36"N, 92°31'3.06"E, 1151 m, subtropical forest, 27 January 2014, coll. D.K.B. Mukhim.</p> <p> <b>Type deposition</b>: Acarological Collection of the “Grigore Antipa” National Museum of Natural History, Bucharest, Romania.</p> <p> <b>Etymology.</b> The specific epithet derives from generic name of the type host and is a noun in genitive case.</p> <p> <b>Differential diagnosis.</b> The new species, <i>Trouessartia dicruri</i> Constantinescu <b>sp. n</b>., is most similar to <i>T. delicatula</i> Gaud, 1952 described from <i>Dicrurus forficatus</i> (Linnaeus) (Passeriformes, Dicruridae) in Madagascar (Gaud 1952). In both sexes of these species, setae <i>d1</i> are present, setae <i>c2</i> are spiculiform and setae <i>sR</i> of trochanters III are lanceolate with acute apex; in males, the translobar apodeme is present, setae <i>g</i> are long and contiguous at bases, the postgenital plaque is present; in females, the supranal concavity is open posteriorly into the terminal cleft, setae <i>ps1</i> are positioned on the mesal margins of the opisthosomal lobes and the external copulatory tube is present. The new species differs from <i>T. delicatula</i> in the first instance being a smaller species (<i>T. dicruri</i> males are 420–452 long, females 500–532 long, vs. <i>c</i>. 575 and 595, respectively in <i>T. delicatula</i>). In males of the new species, the adanal apodemes are without apophyses, the terminal lamellae have a shape of a parallelogram and do not touch each other at the inner margins, and the posterior genital papillae are more distant from the midline than the anterior ones. In males of <i>T. delicatula,</i> the adanal apodemes have a pair of apophyses, the terminal lamellae are semi-ovate, their inner margins touch each other at the level of setae <i>h3</i>, and the anterior and posterior genital papillae are equidistant from the midline. In females of the new species, the setae <i>h1</i> are lanceolate, with acute apex, the interlobar membrane occupies the anterior 1/5 of the terminal cleft, and the ornamentation of hysteronotal shield does not exceed the level of setae <i>d2</i>. In females of <i>T. delicatula,</i> setae <i>h1</i> are spiculiform, the interlobar membrane occupies anterior 1/4 of the terminal cleft, and the ornamentation of hysteronotal shield exceeds the level of setae <i>d2</i>.</p>Published as part of <i>Constantinescu, Ioana Cristina, Cobzaru, Ioana, Mukhim, D. Khlur B. & Adam, Costică, 2016, Two new species of the feather mite genus Trouessartia (Acari: Trouessartiidae) from Asia, pp. 357-374 in Zootaxa 4137 (3)</i> on pages 365-372, DOI: 10.11646/zootaxa.4137.3.4, <a href="http://zenodo.org/record/263571">http://zenodo.org/record/263571</a&gt

Trouessartia longidenticulata Constantinescu, sp. n.

<i>Trouessartia longidenticulata</i> Constantinescu sp. n. <p>(Figs. 1–6)</p> <p> <b>Description.</b> MALE (Figs. 1, 2, 3 A–E; holotype): Length of idiosoma from anterior end to bases of setae <i>h3</i> 300, greatest width at level of humeral shields 140. Length of hysterosoma from sejugal furrow to bases of setae <i>h3</i> 190. Prodorsal shield: length along midline 99, greatest width in posterior part 110, lateral margins not fused with scapular shields, antero-lateral extensions short and rounded, not extending to body margin between bases of legs I, II, surface without ornamentation (Fig. 1). Internal scapular setae <i>si</i> filiform, 8 long, separated by 59; external scapular setae <i>se</i> situated near lateral margins of prodorsal shield, separated by 76. Vertical setae <i>ve</i> represented by alveoli. Setae <i>c2</i> situated on humeral shields, lanceolate, with acute apex, 20 long. Setae <i>c3</i> narrowly lanceolate with acute apex, 16 long. Dorsal hysterosoma with prohysteronotal shield and lobar shield completely separated. Prohysteronotal shield length 140, width at anterior margin 105, lateral margins with shallow incisions at level of trochanters III, dorsal hysterosomal apertures (DHA) absent. Dorsal setae <i>d1</i>, <i>d2</i> present, minute. Length of lobar shield excluding lamellae 40. Apical parts of opisthosomal lobes approximate, separated by narrow terminal cleft; length of this cleft from anterior end to apices of lamellae 18, width in anterior part 4. Lamellae ovate in general shape, their margins with 10 long and sharp denticles, length from bases of setae <i>h3</i> to lamellar apices 16. Setae <i>h1</i> anterior to setae <i>h2</i>. Distance between dorsal setae: <i>c2–d2</i> 65, <i>d2– e2</i> 66, <i>e2–h2</i> 40, <i>h2–h3</i> 14, <i>h2–h2</i> 30, <i>h3–h3</i> 24, <i>d1–d2</i> 34, <i>e1– e2</i> 30. Epimerites I free. Rudimentary sclerites rEpIIa present, roughly ovoid. Genital apparatus situated between levels of trochanters III and IV, length 30, greatest width 14 (Fig. 2). Epiandrum present, small, setae <i>g</i> long and thin, not touching at bases. Anterior and posterior genital papillae equidistant from midline, postgenital plaque absent. Adanal apodemes heavily sclerotized, with narrow lateral membrane, without apophyses. Translobar apodeme present. Adanal shields small, ovoid, bearing setae <i>ps3</i>. Anal suckers 10 in diameter. Anterior ends of epimerites IV not reaching level of setae <i>4b</i>; epimerites IVa present, wide, anterior ends exceeding level of setae <i>4a.</i> Setae <i>4b</i> situated anterior to level of setae <i>3a</i>, setae <i>g</i> situated posterior to level of setae <i>4a</i>. Distance between ventral setae: <i>4b–3a</i> 32, <i>4b–g</i> 66, <i>g–ps3</i> 32, <i>ps3–h3</i> 60. Setae <i>sR</i> of trochanters III filiform, 14 long. Tarsus IV 32 long, modified setae <i>d</i> and <i>e</i> barrel-shaped, each with discoid cap, seta <i>d</i> situated at midlevel of segment on a small extension, setae <i>e</i> situated apically (Fig. 3 D). Legs IV with ambulacral disc extending beyond level of setae <i>h3</i>.</p> <p> FEMALE (Figs. 4, 5, 6 A–E; 4 paratypes): Length of idiosoma from anterior end to apices of lamellar lobar processes 380–400, greatest width 155–160. Length of hysterosoma from sejugal furrow to apices of lamellar lobar processes 260–270. Prodorsal shield shaped as in male, 115–120 in length, 115–125 in width, surface without ornamentation. Setae <i>si</i> thin, filiform, 8–10 long, separated by 67–72, external scapular setae <i>se</i> situated near lateral margins of prodorsal shield, separated by 88–92. Setae <i>c2</i> on humeral shields, lanceolate, with acute apex, 26–30 long. Setae <i>c3</i> narrowly lanceolate, with acute apex, 16–18 in length. Hysteronotal shield length from anterior margin to bases of setae <i>h3</i> 225–235, width at anterior margin 115–120, lateral margins with shallow incisions at level of trochanters III, DHA absent, anterior part with small ovate lacunae, posterior part with big ovate lacunae in central area and small ovate lacunae at margins (Fig. 4). Dorsal setae <i>d1</i> present. Setae <i>h1</i> filiform, 5–6 long, situated antero-mesal to bases of setae <i>h2</i>, 12–16 from each lateral margin of hysteronotal shield. Setae <i>ps1</i> positioned dorsally on opisthosomal lobes, equidistant from outer and inner margins of lobe, closer to bases of <i>h3</i> setae. Distance from bases of setae <i>h3</i> to lamellar apices of lobes 21–26. Setae <i>f2</i> absent. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft together with supranal concavity 82–86, width of cleft at level of setae <i>h 3</i> 15–18. Interlobar membrane occupying anterior ¼ of terminal cleft, distance from its anterior margin to membranous lobar apices 54–56. External copulatory tube absent, copulatory opening situated dorsally, near free margin of interlobar membrane. Spermatheca with primary spermaduct thickened in distal part, length of secondary spermaducts 16–20 (Fig. 6 E). Distance between dorsal setae: <i>c2-d2</i> 73–76, <i>d2- e2</i> 70–76, <i>e2-h2</i> 48–54, <i>h2-h3</i> 36–42, <i>h2-h2</i> 46–54, <i>h3-h 3</i> 26–30, <i>d1-d2</i> 36–44, <i>e1- e 2</i> 31–38, <i>h1-h 2</i> 12–14, <i>h1-h 1</i> 28–34, <i>ps1-h 3</i> 8–10. Epimerites I free. Epigynum 28–31 in length, 72–76 in width (Fig. 5). Epimerites IVa present, wide and short. Setae <i>sR</i> of trochanters III filiform, 1 8–22 long. Legs IV with ambulacral disc extending to midlevel between setae <i>h2</i> and <i>h3</i>.</p> <p> <b>Type material.</b> Male holotype (ANA 610), and 4 female paratypes (ANA 611, ANA 612, ANA 613, ANA 614), ex <i>Pycnonotus cafer</i> (Linnaeus) (Passeriformes: Pycnonotidae), <b>INDIA:</b> Meghalaya, Jaintia Hills, Kharkhana, 25°9'26.99"N, 92°12'24.37"E, 30 m, subtropical forest, 20 October 2014, coll. D.K.B. Mukhim.</p> <p> <b>Type deposition</b>: Acarological Collection of the “Grigore Antipa” National Museum of Natural History, Bucharest, Romania.</p> <p> <b>Etymology.</b> The specific epithet refers to the long spine-like denticles on terminal lamellae in males.</p> <p> <b>Differential diagnosis.</b> The male of the new species, <i>Trouessartia longidenticulata</i> Constantinescu <b>sp. n.</b>, shows a unique character state within the genus <i>Trouessartia</i>, in having the lamellae of the opisthosomal lobes with long and sharp denticles. The new species is very similar to <i>T. latisetata</i> Gaud, 1952, described from <i>Hypsipetes</i> (<i>=Ixocincla) madagascariensis</i> (Müller) (Passeriformes, Pycnonotidae) in Madagascar (Gaud 1952) in having the following features: in both sexes, the external scapular setae <i>se</i> are situated near the lateral margins of the prodorsal shield, the hysteronotal shield has a similar ornamentation and its lateral margins are with shallow incisions at the level of trochanters III, setae <i>sRIII</i> and <i>si</i> are filiform, setae <i>c3</i> are narrowly lanceolate, with acute apex. Males of both species have setae <i>g</i> spaced apart at the bases, the anterior ends of epimerites IVa extend beyond the level of setae <i>g</i> and <i>4a</i>, the adanal apodemes are without apophyses and the translobar apodeme is present. Females of both species have setae <i>h1</i> filiform, setae <i>ps1</i> closer to base of <i>h3</i> setae, the supranal concavity is open posteriorly into the terminal cleft and the external copulatory tube is absent. <i>Trouessartia longidenticulata</i> Constantinescu <b>sp. n</b>. differs from <i>T. latisetata</i> by the following character states: in both sexes, setae <i>c2</i> are lanceolate; in males the prohysteronotal shield and the lobar shield are completely separated. In both sexes of <i>T. latisetata,</i> setae <i>c2</i> are spiculiform; in males, the prohysteronotal and lobar shields are connected.</p>Published as part of <i>Constantinescu, Ioana Cristina, Cobzaru, Ioana, Mukhim, D. Khlur B. & Adam, Costică, 2016, Two new species of the feather mite genus Trouessartia (Acari: Trouessartiidae) from Asia, pp. 357-374 in Zootaxa 4137 (3)</i> on pages 358-365, DOI: 10.11646/zootaxa.4137.3.4, <a href="http://zenodo.org/record/263571">http://zenodo.org/record/263571</a&gt

Two new species of the genus Trouessartia (Acari, Trouessartiidae) from laughingthrushes (Passeriformes, Leiothrichidae)

Two new feather mite species of the genus Trouessartia Canestrini are described from laughingthrushes (Passeriformes: Leiothrichidae) captured in Meghalaya (India): Trouessartia cyanouropterae sp. n. from Actinodura cyanouroptera (Hodgson) and Trouessartia alcippeae sp. n. from Alcippe nipalensis (Hodgson). It is the first time when species of the genus Trouessartia are described from leiothrichids

A new feather mite species of the genus Trouessartia Canestrini, 1899 (Acarina, Trouessartiidae) – an integrative description (morphology and DNA barcoding data)

A new species of the feather mite genus Trouessartia (Trouessartiidae) is described from the Large NiltavaNiltava grandis (Blyth) (Passeriformes, Muscicapidae) in Northeast India (Meghalaya, Jaintia Hills, Shnongrim village). Trouessartia niltavae Constantinescu, sp. n. is morphologically closely related (no phylogenetic meaning) to T. bulligera Gaud, 1968 from Clytorhynchus hamlini (Mayr) (Passeriformes: Monarchidae), sharing in males a unique character within the genus, by having setae e on legs IV hemispheroid, with spine-shaped apex. Males of the new species have the prodorsal shield without ornamentation, the prohysteronotal shield and lobar shield connected, and the terminal cleft parallel sided. Females have the posterior half of the hysteronotal shield ornamented with large ovate lacunae in central area and small elliptical lacunae marginally. To the morphological description of this new feather mite species we added sequence data on the mitochondrial cytochrome c oxidase subunit I gene fragment (COI). The phylogenetic relationships between Trouessartia species are briefly discussed

A new feather mite species of the genus Proterothrix Gaud, 1968 (Acarina, Proctophyllodidae) from the Large Niltava, Niltava grandis (Passeriformes, Muscicapidae) – an integrative description

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Novel in-situ observations on the diel surface activity of the Romanian hamster, Mesocricetus newtoni (Rodentia, Cricetidae), during pup rearing

The Romanian hamster Mesocricetus newtoni is a threatened and cryptic species, with a distribution limited to North-eastern Bulgaria and South-eastern Romania (Dobruja region). Current literature does not provide sufficient data regarding diel activities and behavior of this species, especially under field conditions. In this context, one female M. newtoni, during the rearing period of her four pups, was monitored for ten days using camera traps. For each documented activity, the date, time, age of the individual, type of activity, and duration were recorded. In total, from the 26140 media files, 72968 seconds were recorded as active behaviors. Data analysis revealed that diurnal activity was predominant and documented for all monitored days; however, the animals spent more time per each activity during the night. The nocturnal activity was present but erratic, without significant patterns. No significant differences were observed in the median duration of activities of the adult compared to the immature individuals. Both the adult female and pups spent time exploring the burrow entrance, especially during the day, but immatures were more reserved to leave the burrow than the female. The female used four burrows for rearing the pups. During this time, food storage behaviors and transferring of immatures between burrows, as well as the weaning of the pups were documented. This study demonstrates that M. newtoni exhibits significant diurnal activity, at least in certain ecological and physiological conditions